Considering Safety in the Transportation Planning Process
Chapter 3: Incorporating Safety Into Short-Range Planning
The long-range transportation plan is multi-modal and fiscally constrained. It has at least a 20-year horizon and is updated every 3 years in air-quality non-attainment areas and every 5 years in other areas. The long-range plan includes financially constrained, practical projects to achieve the needs of the transportation system. The plan is carried out through the transportation improvement program (TIP) for metropolitan areas and through the statewide transportation improvement program (STIP) for all other areas. The TIP and STIP are the primary programming documents for a region or state. They must cover at least 3 years and be updated at least every 2 years. Similar to the long-range plan, these short-range plans are multi-modal and financially constrained.
Programming Process
The TIP is a multi-modal programming document for defined projects. Through the programming process, transportation planners evaluate projects for funding and inclusion in the TIP. Projects are chosen on the basis of selection criteria. After the TIP or STIP is approved, projects advance to the project development stage.
Transportation planners can incorporate safety into the programming process by empowering their member agencies, identifying safety as a priority in the selection of projects for the TIP or STIP, and advocating the consideration of safety elements in proposed projects.
Empowering Agencies and Jurisdictions
Transportation planners can improve transportation system safety by assisting their member agencies, districts, and jurisdictions as follows:
Provide Data: Transportation planners can provide their member agencies with safety data, primarily crash data. Because planning agencies are traditionally not keepers of crash data, the planning agency would only facilitate agencies in obtaining the data. However, transportation planners work with the agencies that maintain the data and can distribute the data to the member agencies or jurisdictions or facilitate their obtaining the data. The actual arrangement varies by agency.
Conduct Crash Analysis: Many member agencies lack the resources (such as tools, staff, and expertise) to analyze crash data. State transportation planners and MPOs, which have tools such as GIS that facilitate crash data analyses, could provide crash analysis as a service to member agencies or jurisdictions. State transportation planners and MPOs could also work cooperatively with member agencies or jurisdictions and assist them in conducting the analysis.
Provide Crash Analysis Tools: Transportation planners can empower agencies to identify safety projects by providing the tools necessary to analyze crash data. These tools may range from comprehensive crash analysis software to simple maps of high crash locations.
Identify Target Areas: Transportation planners can identify target areas or systemwide safety problems (such as red signal violations) that need to be addressed. Most likely, these areas or problems would be identified through special studies. On the basis of the special studies findings, the transportation planner could educate their member agencies and jurisdictions on the importance of the issue and suggest transportation strategies and investments to mitigate the problem.
By empowering the member agencies and jurisdictions, transportation planners can increase the consideration of safety in projects proposed for the TIP or STIP. The quality of the projects proposed may also be increased.
Safety in the Project Selection Criteria for the TIP or STIP
The project evaluation and selection process varies according to the MPO or state planning office and the project funding category (for example, congestion mitigation and air quality, bridge, and STP). The TIP or STIP should outline the process for selecting projects for the financially constrained program. Project selection can be both quantitative and qualitative and should be based on screening, scoring, and programming criteria. Candidate projects are drawn from the conforming, fiscally constrained transportation plan. The TIP or STIP must be consistent with the long-range plan and, as such, the TIP or STIP projects must meet the goals set forth for the transportation system through the long-range plan. As described in the previous chapter, including safety as one of the transportation system's goals is vital to incorporating safety into the transportation planning process. Once safety is identified as a goal of the transportation system through the long-range plan, the safety goal can be used to select and prioritize projects for the TIP or STIP.
In most jurisdictions, the process of selecting projects is highly competitive. The available resources to fund the TIP or STIP often are not enough to meet all the identified needs of a jurisdiction. Planning agencies are faced with the delicate task of allocating the resources among competing priorities within their jurisdictions. If safety is not clearly defined as a priority, safety projects may not be funded.
Even when long-range safety goals are included in the plan and validate safety as a priority, safety projects may not be selected for the TIP or STIP if the process is not objective. If the projects will bring improvements in safety only in the long term, they may be excluded to accommodate projects that will bring near-term improvements and address other objectives such as reducing congestion.
An objective selection process can help to secure funds for safety projects in the TIP or STIP. Planning agencies can accomplish this by including safety goals and objectives in the long-range plan and then constructing a project scoring system to evaluate projects based on the goals and objectives of the long-range plan. A properly devised scoring system evaluates the level to which each proposed project advances the transportation system toward the goals and objectives of the long-range plan, including the safety goals and objectives. Selecting projects under this method should facilitate the attainment of long-range goals, project by project.
Many MPOs and state planning agencies use safety as a criterion by which to prioritize TIP or STIP projects. Safety can be assessed quantitatively (for example, based on the number of fatal and injury crashes the project prevents) or qualitatively. For qualitative safety assessments, expert judgment can be used to determine how safety will be changed by the proposed project.
The Delaware Valley Regional Planning Commission (DVRPPC) TIP Project ScoringDVRPC developed a process for ranking projects proposed for inclusion in the TIP based on a series of questions that are integrated with the goals, policies, and actions of the MPO's long-range plan. There are seven goals in the long-range plan. The importance or priority of each goal is expressed with a weight. The goals and weights are as follows:
Each goal has an objective, referred to as a process. The objective of the safety and security goal is to improve the safety and security of the transportation system's user/customer through programs or improvements that eliminate or lessen safety hazards. Each process also has a series of "yes" or "no" questions. Five or ten points are allocated for each question. Questions answered "no" receive zero points. Questions answered "yes" receive the maximum number of points. The questions in the safety and security process are as follows:
The points are totaled for each question in the process and multiplied by the weighting factor. All of the processes are totaled together to obtain the project score. These project scores are then considered in the selection of projects. |
Including Safety as a Priority in Project Selection for the TIP in Urban Areas
A survey of MPOs and their practices in scoring projects for the TIP found that many included safety as one of the scoring criteria (1). Some of these MPOs are highlighted in the following examples.
SANDAG, the MPO for the San Diego, California, metropolitan area uses safety as 10 percent of the TIP selection criteria for state highway projects based on the project's highway accident rate. Safety is 19 percent of the selection criteria for Regional Arterial System projects. Scoring is based on a subjective description of the project's accident problems and project safety features.
OKI, the MPO for the Cincinnati, Ohio, metropolitan area uses safety as 10 percent of the TIP selection criteria for highway projects. Scoring is based on a subjective rating of the project's accident history. It is similarly used as 5 percent of the project selection criteria for highway projects in the flexible funding criteria.
Metroplan, the MPO for the Little Rock and North Little Rock, Arkansas urban area uses safety as a criterion in the selection of transit projects; roadway, bridge, and intersection improvement projects; and enhancement projects. Safety is 12 percent of the project score for each of the three project categories. The safety measure used for each is a subjective assessment of the project's ability to eliminate hazards.
Bi-State Regional Commission is the MPO for the Quad City metropolitan area of Illinois and Iowa. The regional planning agency uses safety as 20 percent of the project score for highway projects. The scoring is based on the project's past accident history, severity of those accidents, and accident rate.
Mid-America Regional Council (MARC) is the MPO for the bi-state Kansas City region. Safety is considered in the TIP project score for both highway and enhancement projects. Safety is 20 percent of the project score for Missouri roadway projects, 10 percent of the project score for Kansas bridge projects, 30 percent of the project score for Kansas roadway projects, and 15 percent of the project score for enhancement projects.
The Denver Regional Council of Governments (DRCOG) uses safety as part of their project evaluation scoring for the TIP. There are 8 project categories evaluated by DRCOG including:
- Maintenance projects such as highway reconstruction and resurfacing projects,
- Safety projects,
- Management projects such as operational projects,
- Transit projects such as transit operations or passenger facilities projects,
- Highway projects such as widening projects,
- Bicycle and pedestrian projects,
- Elderly and disabled and non-urbanized transit projects, and
- Other projects such as special studies.
Projects that are defined as safety projects are selected by the Colorado Department of Transportation (CDOT) based on their benefit/cost ratio. However, other projects can also have safety impacts including operation improvement projects, roadway widening projects, interchange reconstruction projects, and bicycle and pedestrian projects. The consideration of safety in these projects varies depending on the type of project. For example, in operational improvement projects, the safety evaluation represents 10 of the 126 points available. Points are awarded based on the estimated reduction in crashes that project is expected to bring about and the project's weighted crash rate compared to the statewide average.
Encouraging the Consideration of Safety in Proposed and Planned Projects
Transportation planners can improve the safety of the system by advocating safety consideration. Projects programmed through the TIP or STIP do not have to be expressly identified as safety projects to improve transportation system safety. Safety improvements can also be accomplished as add-on items to proposed projects. For example, a highway-widening project could also include a provision for new sidewalks and improved pedestrian crossings and pavement markings. Often, it is cost effective to make safety improvements while other improvements are being made. The same is true of operations and management projects. These projects often consume large amounts of an agencies budget and have a large potential for including safety improvements.
Transportation planners can suggest to member agencies and jurisdictions that they include safety elements in all projects recommended for inclusion in the TIP or STIP. The transportation planner may need to examine aspects of the proposed projects and identify elements where safety can be improved.
Dedicated Safety Programs Implemented Through the TIP or STIP
Some transportation safety projects are part of a dedicated safety program implemented through the TIP or STIP. These programs usually involve the identification of hazardous sites in need of safety remediation. Projects can be selected by crash data analysis and from citizen complaints, professional input (such as police officers), and road or neighborhood safety audits. They may also be incident motivated or part of a targeted, systemwide improvement such as increasing the clear zones on all rural highways in the jurisdiction.
Crash Data Analysis
Transportation planners or their member agencies and jurisdictions can use past crash histories to identify locations needing safety improvements. Ideally, this analysis should identify not only those sites with safety deficiencies, but also those sites that can be reasonably improved through transportation investment. This method of identifying safety projects is described in detail in Chapter 4.
Citizen Input through Public Involvement Process
Users of the transportation system are often aware of site safety deficiencies before the sites are identified through crash data analysis. Transportation planners can use citizen input to identify sites in need of safety improvements. This can be accomplished informally through the receipt of complaints or formally through a formal public involvement process or citizen committees.
Incident Motivated
Highly publicized traffic incidents can result in public outcry for safety remediation. Although reactive activities are not usually associated with planners, highly publicized incidents can help to identify potential safety projects. Incident-motivated projects also provide an opportunity for planners to increase awareness of the importance of safety in their jurisdictions. Highly publicized crashes often bolster public support for safety, at least in the short term. Unfortunately, the importance of incorporating safety into the planning process is often not fully realized until such incidents occur. Planners can use the safety awareness that incidents generate to increase public support for safety as a long-range goal. Planners can also use this awareness to identify safety projects that should also be selected for the TIP or STIP in the short term.
Road Safety Audits
All the methods described so far to identify potential safety projects for the TIP or STIP have been mainly reactive to safety deficiencies. Road safety audits (RSAs) are a potential tool for assessing safety deficiencies proactively. FHWA describes an RSA as an assessment of the crash potential and safety performance of an existing road or proposed project. An RSA consists of a formal examination of an existing or future roadway by an independent team of qualified engineering, enforcement, and human factors professionals. It is a formal and independent review for assessing the multi-modal safety performance of the roadway. An RSA results in a brief report identifying the safety problems and potential solutions.
Currently, the role of transportation planners in the RSA process is largely undefined. Because of their emphasis on design, RSAs are fairly inconsistent with the structure of transportation planning. However, because of the desire to use RSA as a tool to proactively increase safety, there is potential for collaboration between transportation planning and RSA.
One way that transportation planners could be involved in RSAs is through the role as a facilitator. Transportation planners can help assemble the RSA team. The team should consist of experts from all disciplines of highway engineering, including traffic engineers, design engineers, and safety engineers, and should be supported by human factors experts, law enforcement experts, and risk management experts. Team roles could be adapted depending on project needs or agency resources. The audit team members should be independent from those involved in designing or constructing the project.
Road Safety Audits in the United StatesAn FHWA initiative introduced the concept to the United States in the late 1990s. Both Pennsylvania and Minnesota were selected to conduct pilot studies of RSAs in the United States to determine if the safety audit process is a valuable tool, and if so, how to expand its use to additional areas. Both states found that the process was beneficial as a tool for improving safety. On the basis of the pilot program, PennDOT decided to expand the program within its organization (2). The safety audit process has now been expanded to all Pennsylvania districts. Currently, the safety audits are only being used to review preliminary designs for construction projects and not for assessing how safety for existing facilities can be improved. Other states have been involved in the FHWA safety audit initiative including California, Kentucky, Missouri, Montana, Ohio, New York, Rhode Island, Texas, Utah, Vermont, and Wyoming. FHWA will continue to partner with states and local jurisdictions to assess the feasibility of integrating the RSA system into all phases of roadway planning, preliminary design, final design, construction, and operations (3). |
Additional InformationThe Institute of Transportation Engineers (ITE) with financial support from FHWA has developed a Road Safety Audits web site. The site has a variety of resources related to safety audits, links to other web sites, and a discussion forum for safety professionals. The web site can be accessed at: http://www.roadwaysafetyaudits.org/. |
Targeted Safety Improvements
Dedicated safety improvements identified for implementation through the TIP or STIP may be part of a targeted safety improvement program (for example, one that increases the clear zone on rural highways). Sites for the targeted improvement program may be identified through crash data analysis or simply based on the characteristics of the site. Using the clear-zone improvement example, a roadway segment may be identified for improvement through the program because of past run-off-the-road crashes or because the site has a narrow shoulder and hazards (such as utility poles) close to the roadway.
Targeting Low-Cost Improvements: PENNDOT's ApproachPENNDOT has developed a targeted program to implement low-cost improvements to reduce the number of fatalities statewide. The low-cost improvements are being implemented by district safety engineers through the Safer Travel Strategic Focus Area (SFA) program at high crash segments and spots. The program concentrates on the following 12 crash categories:
The Bureau of Highway Safety and Traffic Engineering (BHSTE) developed a toolbox of low-cost highway safety improvements to address these 12 categories. The improvements were developed based on analyses of collision data for the state. The following are examples:
District engineers are asked to include a plan and approach to meet their target fatality reduction goal as part of their District Business Plan. The progress of each area is reported quarterly. The primary measure of progress is the number of lives saved annually. A secondary measurement is the number of low cost improvements implemented. Each category has minimum criteria for the number of clustered collisions deemed necessary for a segment to be considered for low-cost improvements. Improvements have been developed for each category. Crash-reduction factors are given for each category by improvement type. To meet its goal for reductions in fatalities, each district must implement low-cost improvements at locations with the highest potential for a reduction in crashes based on the crash data. Each district must maximize its resources to meet its targets (4). |
Tools for Transportation Programming
Tools are available to help transportation planners incorporate safety into the transportation programming process. These tools include benefit-cost analysis methods, crash reduction factors, and project analysis software that also performs benefit-cost analysis.
Benefit-Cost Analysis
When transportation planners are evaluating whether to proceed with a transportation investment, they analyze the benefits and costs of transportation projects or policies. A benefit-cost analysis usually compares alternatives although it can be used to decide whether to proceed on a specific project. Because of the limited funds available for transportation projects, benefit-cost analysis helps transportation planners allocate limited funds to maximize societal benefits.
The benefits and costs of a project or policy usually extend beyond the direct costs (that is, capital costs, operating costs, and revenue). Transportation planners must also consider benefits and costs that do not have a dollar value attached to them. Using a technique called monetization, the planner can assign a dollar value to indirect benefits and costs of a project. This allows both the direct and indirect costs and benefits of a project to be considered systematically in the analysis.
The safety benefits of a project are usually considered as reductions in crashes. When monetizing the benefits of reduction in crashes, the crash severity is important; that is, reducing the number of fatal crashes has a greater benefit than reducing the amount of property-damage-only crashes.
Estimating Project Benefits: Crash-Reduction Factors
When considering the safety benefits of a project, transportation planners first estimate the projected reductions in crashes that the project will bring about. To optimize the use of available funds, many agencies employ crash reduction factors, also called accident reduction factors or accident modification factors, to estimate the safety benefits of highway improvements or design alternatives. A crash-reduction factor is a measure of the effectiveness of a specific transportation improvement. It quantifies the effectiveness of the improvement designed to reduce the frequency and/or the severity of crashes at a location.
Crash-reduction factors are usually expressed as a percent reduction in the number of crashes attributed to the specific transportation improvement. The percent reduction is multiplied by the expected crash frequency without the improvement. This calculates the reduction in crashes that the improvement is estimated to bring about. Often, this reduction is just applied to the crash frequency from the previous year or from an average of the last 3 years. However, to account for the effect of an unusually hazardous year (regression to the mean), the estimate of the expected number of crashes without the improvement may be more appropriately derived from a predictive model if available (5).
The crash-reduction benefits of a highway improvement or design alternative are sensitive to the unique characteristics of the transportation environment. High-quality crash-reduction factors are necessary to provide a reliable estimate of safety benefits. FHWA has encouraged states to produce their own crash-reduction factors. States such as California, Indiana, South Dakota, and Florida have done so and have published the resulting factors. The published factors could be used prudently by other agencies to conduct benefit-cost analysis, especially because developing crash-reduction factors requires a large amount of effort. However, crash reduction factors are highly sensitive to the locality of the data that produced the factor. If jurisdictions use crash-reduction factors developed by other jurisdictions, they should evaluate the transferability of such factors. In addition, agencies should understand the data used to create the factors so that the factors can be appropriately applied to the crashes at the location of the proposed improvement. For example, should crashes involving alcohol be included in the calculation? Some crash-reduction factors are developed only from the number of crashes that relate to the proposed improvement. Crashes that were the result of impaired drivers may have been excluded from the calculation of the crash-reduction factor and therefore should be excluded from the calculation of the estimated reduction in crashes.
Developing Crash Reduction Factors for an MPO AreaSEMCOG developed a set of crash-reduction factors for use in estimating the benefits of safety projects and improvements in its MPO area. The MPO developed the set of crash-reduction factors by researching several data sources including the Kentucky Transportation Research Program, the Kentucky Transportation Center, Texas DOT, and MDOT. They synthesized the results and decided on a default crash-reduction factor for a group of countermeasures. These factors are given to local jurisdictions to be used as default crash-reduction factors. In their benefit-cost analyses submitted for each safety project, local communities can use different values if supporting documents are provided. Jurisdictions are encouraged to use their own data to develop factors and then provide copies of such new information to the SEMCOG Transportation Department for use in subsequent development/ refinement of crash-reduction factors (6). |
Methods to Develop Crash-Reduction Factors
The two predominant methods for developing crash-reduction factors are before-and-after studies and cross-sectional analysis. Before-and-after studies determine the safety effect of an improvement by comparing the number of crashes occurring before and after a transportation improvement. Cross-sectional analysis compares the differences in safety across locations. The differences in the relative safety of the various locations are attributed to disparate aspects of the location environments. The results of either of the two study methodologies are then analyzed using regression, confidence intervals, likelihood functions, and others to develop crash-reduction factors.
The potential drawbacks (threats to the validity) of before-and-after studies are well known (regression to the mean, history, maturation). Some of these drawbacks can be overcome with a well-designed study although the data requirements may become restrictive. The drawback of using the cross-sectional analysis method to develop crash-reduction factors is that it is difficult to attribute the variation in safety between locations to particular transportation improvements. When developing crash-reduction factors, the study should be carefully designed and the findings should be interpreted with care.
Applying Multiple Crash-Reduction Interventions
Crash-reduction factors estimate the reduction in crashes from an individual transportation improvement such as adding a signal, widening the travel lane, or increasing the shoulder width. However, proposed transportation projects will often involve more than one of these improvements. Unfortunately, the crash-reduction potential of these improvements is not additive; that is, if increasing travel lane width has a crash reduction factor of 30 percent and increasing shoulder width of the travelway has a crash reduction factor of 40 percent, both improvements together should not be expected to result in a 70 percent reduction in crashes.
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The generalized formula (7) for estimating the combined effect of implementing a number (n) of transportation improvements is: 
[3-1]
where,
F = estimated annual crash frequency without improvement, n = the number of improvements,
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= estimated annual reduction in crash frequency,
= crash reduction factor (expressed as a percent) for the first improvement, and
= crash reduction factor (expressed as a percent) for the second improvement, etc. to the nth improvement.
Monetizing Estimated Benefits
After the reduction in total crashes, injury crashes, or fatal crashes are estimated for a proposed project, the reduction must be translated into a benefit that can be systematically evaluated in relation to the costs. The translation of the benefit into monetary units is the process of monetization. To monetize crash-reduction benefits correctly, the analyst needs cost estimates for motor vehicle crashes.
In a 1994 report, FHWA estimated the costs of a fatal crash to be $2,600,000, an incapacitating injury (type A) to be $180,000, an evidential injury (type B) to be $36,000, and a possible injury (type C) to be $19,000; property-damage-only crashes were priced at $2,000 (8). The methodology suggests annually increasing the costs by the gross domestic product (GDP) implicit price deflator. Thus, in 2002, these costs are approximately $2,981,000 for a fatality, $206,000 for an incapacitating injury, $41,000 for an evidential injury, $22,000 for a possible injury, and $2,300 for a property-damage-only crash.
Additional Information on Benefit-Cost AnalysisThere are several approaches to benefit-cost analysis. In its Toolbox for Regional Policy Analysis, FHWA presents various methodologies and programs that can assist planners in conducting benefit-cost analysis. The toolbox is available on the Internet at http://wwwcf.fhwa.dot.gov/planning/toolbox. ITE publishes the Transportation Planning Handbook. It provides information on the state-of-the-art of established practice in transportation planning. The handbook includes guidance for transportation planners conducting a benefit-cost analysis and a discussion on monetizing the benefits of crash-reduction measures. The American Society of Civil Engineers (ASCE) is developing guidance for the application of benefit-cost analysis in transportation planning. The guidance is being developed through ASCE's Committee on Urban Transport Economics and Policy. The objective of the project is to help broaden the extent to which benefit-cost analysis is used for transportation policy and investment decision-making and to help improve the quality of analysis. The final product will be a web site devoted to benefit-cost analysis in transportation planning. The web site, currently available as a work in progress, can be accessed at: http://ceenve.calpoly.edu/sullivan/cutep/cutep_bc_ outline_main.htm |
Project Analysis Software
TELUS Software
The Transportation, Economic, and Land-Use System, or TELUS, is a data-management and decision-support program created to assist transportation agency planning. The thrust of the system's development was to help transportation agencies meet the transportation planning and programming requirements of TEA-21. TELUS helps planners meet the safety and security goal as well as the other six goals in the TIP or STIP scoring process. The system has a scoring module for prioritizing TIP or STIP projects. TELUS allocates 100 points for each of the 7 TEA-21 objectives. Concerning the safety objective, points are allocated for reducing personal injury, fatalities, and property damage; denying unauthorized access to the system; assisting the monitoring or patrolling of the system; increasing access to accident incidences and/or disabled motorists; enhancing or adding to the system of bike lanes and sidewalks; enhancing the movement of pedestrians across intersections and the public safety of pedestrians; and contributing to a reduced number of elderly drivers.
The first version of the system also contains a planning analysis module that calculates the degree to which the resulting TIP or STIP meets the seven TEA-21 planning objectives. Future versions will include economic and land-use components, providing further assistance for incorporating safety in the planning process.
Additional InformationMore information and the software are available to transportation planners at: http://kimon.njit.edu/TELUS/ |
Arizona Local Government Safety Project Model
Often, local governments lack the resources for conducting in-depth analysis of highway safety needs to identify potential safety projects in their jurisdictions. In response to this lack of resources, the Arizona DOT developed the Local Government Safety Project (LGSP) analysis model. The model is intended to help identify sites and implement strategies for local safety projects. It provides local governments with an efficient and justifiable means of assigning priority to potential projects in a local safety program so that resources can be appropriately allocated among traffic safety alternatives. It is focused on the development of implementation strategies for local safety projects through the synthesis of data such as traffic volume, average speed, and type and design of the roadway.
The LGSP model was incorporated in a Microsoft Access program for users. The model consists of two parts. The first part selects a subset of locations within the area of concern based on user-defined parameters such as the weighting method for injuries sustained. On the basis of the user parameters, the model generates reports that identify hazardous sites. The reports include information on crash frequency, severity, and costs of the crashes for each location. It also provides specific details about each of the sites (such as roadway type) and details about the crashes that occurred at those sites (such as weather). The model does not select treatments for the user because it is assumed that no one can understand the unique needs of each site better than local engineers. Safety treatments are selected by the local engineer on the basis of a traditional engineering safety analysis. The model output is only one of many data sources that the engineer considers in the site analysis.
The model also generates a list of similar sites for each of the hazardous sites. This comparative list can be useful to the engineer for before-and-after evaluations of the selected countermeasures once they are implemented.
In the second part of the model, the user inputs the possible safety treatments for each of the sites. Each treatment is assigned an effectiveness value. The user can input the projected effectiveness of the treatment or use default values included in the model. From the input of possible safety treatments and effectiveness values, the model calculates an expected benefit for each project and returns a benefit-cost analysis, the results of which are used to prioritize projects in the area (8).
Decision Support System
The computer software program Decision Support System (DSS) was developed for U.S. DOT to assist planners' decisions about investments in highway transportation infrastructure. The program aids planners in performing an economic evaluation of proposed reinvestments and/or modest new highway investment projects. Predicted reductions in accidents are one of the project benefits evaluated.
Safety Resource Allocation Program
The Safety Resource Allocation Program (SRAP) is a software package that contains three computerized methodologies developed by FHWA to aid highway safety planning decisions by prioritizing projects on the basis of their benefits and costs. The methodologies include an incremental benefit-cost analysis, integer programming, and dynamic programming. Using the software, a transportation planner can maximize the total net accident savings within the available budget by selecting the optimal mix of accident locations and the preferred countermeasure at those locations. A user's manual was also developed and is available from FHWA (9).
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DSS, SRAP, and other applicable software can be ordered through the FHWA-designated software distribution center, PC-TRANS. PCTRANS can be accessed on the Internet at: http://www.kutc.ku.edu/pctrans/ |
Safety Analysis for Railroad/Highway Grade Crossings
The Federal Railroad Administration (FRA) requires a benefit-cost analysis as a condition for receiving funds for railroad/highway grade crossing improvements (Section 130 funds). These funds are for the elimination of hazards associated with railway/highway crossings including the separation or protection of grades at crossings, the reconstruction of existing railroad-grade crossing structures, and the relocation of highways to eliminate grade crossings.
FRA requires that the benefit-cost analysis follow the Administration's definition of benefits and costs (10). Benefits include safety benefits (savings in lives, injuries, and crashes), travel time savings by highway vehicles, environmental benefits (in reducing vehicle emission due to idle time at grade crossings), vehicle operating cost savings (for both motor vehicles and rail cars), network benefits (on average queue lengths for vehicles approaching highway segments), and local benefits (grade crossing improvements to the local community).
Costs include the capital outlays involved in the construction, the annual operating and maintenance costs, and other life cycle costs (for example, the need to hire specialists to change particular components). FRA has produced a software package for conducting benefit-cost analysis at railroad/highway crossings (11). The package, called GradeDec 2000, can be downloaded from the FRA web site.
Incident Management
Incident management is the process of managing multi-agency, multi-jurisdictional responses to highway traffic incidents. Traffic incidents, if not properly managed, can greatly affect transportation system performance. Not only do traffic incidents increase congestion and reduce capacity, they also decrease the safety of the entire system. In addition, rescue personnel response may be slowed by the congestion caused by the incident, further endangering the safety of the motoring public.
Transportation planners can facilitate incident management programs by acting as coordinators, increasing the awareness of the need for an incident management system, or strengthening the support and cooperation between member agencies.
MPO Facilitation of an Award Winning Incident Management ProgramThe Ohio-Kentucky-Indiana Regional Council of Governments (OKI) is a pioneering MPO in incident management. The Cincinnati region MPO facilitated the bi-state "buy-in" of the region's incident management system by completing both the feasibility study for the incident management system and the preliminary engineering design study. Because of OKI's work, the resulting system, the Advanced Regional Traffic Interactive Management and Information System (ARTIMIS), now serves 51 jurisdictions in Ohio and 20 in Kentucky. ARTIMIS covers 88 miles of the region's busiest highways. Although the lead role for the project implementation was transferred from OKI to the State of Kentucky, the MPO continued to play a facilitating role throughout the ARTIMIS implementation. The MPO also facilitated the operation of the system by establishing a partnership of incident management agencies in the region (12). |
The goal of an incident management system is to coordinate the response to the incident efficiently so that the impact on public safety, traffic conditions, and the local economy is lessened. States and metropolitan areas implementing incident management systems experience a marked decrease in secondary crashes, a decrease in incident response times, increased delay savings due to reduced congestion, reduced emissions, and increased throughput.
Incident management systems use intelligent transportation systems such as closed circuit televisions, vehicle detectors, signal timings, and variable message boards to detect, verify, respond to, and clear incidents faster. The systems require coordination between many diverse agencies, especially in metropolitan areas that span multiple jurisdictions. MPOs can coordinate the incident management system across jurisdictional boundaries.
In metropolitan areas where it is not the coordinating body of the incident management program, the MPO can be effective in other areas. In Milwaukee, Wisconsin, an incident management system was put into place after a joint study by the regional planning committee and the state DOT found that an incident management system would improve the safety and the flow of the city's transportation system. The MPO can also provide useful information to other jurisdictions coordinating an incident management program. Several MPOs already coordinate incident management in their metropolitan areas including Johnson City Metropolitan Transportation Planning Organization, Tennessee; Ohio-Kentucky-Indiana Regional Council of Governments (OKI); Atlanta Regional Commission (ARC), Georgia; and Puget Sound Regional Council (PSRC), Washington.
Incident management systems require funding. Identifying incident management as one of the goals and objective of the planning jurisdiction can help to secure funding and potentially increase transportation system safety.
Additional InformationMore information is available to transportation planners on incident management and other ITS measures that can increase safety through U.S. DOT's web site on ITS: http://www.its.dot.gov |
Special Studies
Transportation planners conduct a range of special studies to accommodate and understand the needs of transportation system users. Special studies that target or have elements that target the safety of the transportation system may include the aging population and its changing mobility needs, needs of pedestrians and bicyclists, transit access, and systemwide safety problems such as speeding. Transportation planners' roles as coordinators can increase the safety of transportation systems through these special studies.
Balancing the Needs of Heavy Vehicles and Safety ConcernsIn Syracuse, New York, residents were concerned about the effect of truck traffic on the safety of city streets. Citizen complaints prompted truck restrictions to be arbitrarily placed throughout the city without any concern for the needs of the trucking industry or the effect of individual restrictions on surrounding routes. The maze of restrictions and lack of guidance often led trucking companies onto routes that could not safely accommodate the vehicles. Citizen concerns prompted a study by the MPO, the Syracuse Metropolitan Transportation Council (SMTC). SMTC conducted a comprehensive review and analysis of truck routes, related signage, and constraints on those routes within the city. SMTC reached out to members of the trucking industry and the community and assembled a combined Study Advisory Committee (SAC) and Stakeholders group to provide guidance and review during the study. The group included six interested public agencies and six private companies. Other private companies provided input through written correspondence. By facilitating the involvement of all interested parties, SMTC was able to develop a designated truck route that satisfied the needs of the city and the trucking industry. The systematic approach resulted in a new recommended truck route system with fewer through truck routes within city limits (13). |
Initiating Special Studies
Planning activities for an MPO or at state planning office are specified in the work program and may include provisions for special studies to identify system needs and solutions. A special study may be initiated in various ways. The transportation planner may have to promote the need for the special study so that funds are available and so that the study is included in the work program. For studies on increasing the safety of the transportation system, the transportation planner would serve as an advocate for safety.
A special study also can be initiated through public support. Highly publicized traffic incidents can result in public outcry for safety remediation. Although reactive activities are not usually associated with planners, incident motivation studies can offer planners the opportunity to increase safety in their jurisdictions.
Examples of Special Studies Conducted by Planning Agencies
Planners can perform various specialized, short-range studies to increase the safety of the transportation system. The findings of the studies may be implemented through short- or long-range planning activities. Examples of special studies that incorporate safety into transportation planning are described in the following sections.
Delaware Valley Elderly Study
DVRPC, the MPO for the Delaware Valley region, studied the mobility needs of older drivers. The study of older travelers reviewed the location and scale of the region's current and forecasted elderly population and identified alternatives to the private automobile including rides from family and friends, walking, public transit, demand-responsive paratransit services, taxis, and public and private senior transportation services.
On the basis of the study findings, the MPO developed transportation and non-transportation recommendations to improve the mobility and quality of life of older residents in the metropolitan area. Recommendations included revising plans and zoning regulations in suburban municipalities to encourage increased densities, mixed-use communities, and service clustering to provide walkable access to services. Although this recommendation is intended to plan a change in land use, the net effect is to improve transportation system safety because fewer older drivers will be on the area's highways. A similar recommendation called for increased access to regionwide transit and a marketing campaign to encourage older drivers to use transit. The MPO also recommended that pedestrian facilities be improved to increase the safety of the transportation system for pedestrians and encourage older citizens to forgo private automobile use (14).
Two School Safety Studies
The Tri-County Regional Planning Commission (TCRCP), the MPO for the counties around Lansing, Michigan, introduced the "Bike and Walk" program to bolster support for pedestrian and bicycle safety. The increased support and awareness resulted in the creation of bicycle lanes and the rebuilding of alleys. TCRCP also conducted a community walkability audit (CWA).
The "Safe Ways to School" program was initiated in the State of Florida. It is a joint effort of the state's DOT, Department of Education, community traffic safety teams, and school safety teams. The program brings together state, county, and local policy-makers, planners, and school officials to increase the number of children who walk and bicycle to school by designating and improving safe routes. The pilot program was initiated at 10 elementary schools. In three of the pilot schools, regional planners or MPO planning staff served as members of the school safety teams. Many of the improvements recommended through the program were funded through the transportation improvement programming process (15).
Making Secane a Walkable Community
Secane is a suburban neighborhood that surrounds a commuter rail station in the Delaware County of Pennsylvania. DVRPC, the MPO for the Delaware Valley region, conducted a study of pedestrian travel and transit access in the area. From the study findings, it produced a report proposing a program of capital improvements to make pedestrian travel in Secane safer and more appealing.
County planners nominated Secane for the study because the community's residential density and mixed land uses were conducive to high walking rates, but also because its walking environment needed improvement. The study analyzed the history of motor vehicle crashes with pedestrians; design issues that may have contributed to those crashes; existing pedestrian facilities; elements of the environment that are inhospitable to pedestrian traffic; and deficiencies and shortages in crosswalks, bus stops, and transit amenities.
Incorporating Safety Into Corridor Planning
Corridor planning is an important tool for improving the safety of the transportation system. It provides the opportunity to incorporate safety at the broader planning level analysis. Exhibit 3-1 illustrates the levels of transportation planning. MPOs and DOTs planning offices are more involved with the broader levels of planning. As the levels become more site specific, MPO and DOT planning office involvement decreases while implementing agency involvement increases. The corridor level of planning, a broad level below regional planning, may encompass multiple routes and various modes of transportation between two major destinations or urban areas. Corridor-level planning may be composed of multiple smaller projects within the corridor on major arterials, minor arterials, transit routes, and multi-use trails. Through corridor planning, safety issues can be considered and addressed earlier in the process.
Exhibit 3-1
Levels of Transportation Planning
Corridor planning explores transportation safety beyond a single intersection, transit stop, crosswalk, or segment of highway. Many corridor studies are motivated by safety concerns or by a combination of safety concerns and congestion. These studies help to identify safety deficiencies that result in projects for the TIP or STIP. Projects along corridors can be coordinated to achieve the safest system of transportation within the corridor across multiple modes and routes. Corridor studies can also identify deficiencies in the junctions between modes.
Transportation planners have an important role in corridor studies. They are often the coordinating body for the multiple agencies needed to conduct a corridor study. These agencies include local and state highway agencies, transit agencies, railway agencies, port authorities, business owners, law enforcement, citizens, and community groups. Transportation planners can assure that adequate representation is provided in the corridor planning committee for all users including transit riders, pedestrians, and bicyclists. This helps to ensure that the safety needs of all transportation system users are considered in the corridor study.
Various types of data are needed for corridor safety studies including volume, land use, and crash data. Transportation planners can provide or assist the committee in obtaining the safety data needed for the corridor study.
MPO's Role in Corridor Planning in the Delaware Valley RegionDVRPC, the Delaware Valley MPO, assembles a committee for each corridor being studied. All interested bodies are represented on the committees, including municipalities, transit agencies, and community groups. After DVRPC receives data on the corridor from the PennDOT it superimposes the data on a map of the corridor. The superimposed data contains information on pavement, crashes, bridges, and so forth. On the basis of the data, the committee develops a characterization of how it would like the corridor to move forward. The committee must decide on the balance between corridor needs (for example, safety and capacity). Programming improvements along the corridor are then suggested globally. |
Incorporating Safety Into Transit Planning
Transit agencies have a primary concern with safety and security. Because they are responsible for transporting passengers, they have extraordinary liability concerns. In metropolitan areas, transit agencies and MPOs jointly decide how to address TIP transit projects.
Transit agencies vary widely in size and service, and each has a unique method for management and operation. However, for the most part, these agencies lack a structured approach for integrating safety and planning. Transit agencies address safety and typically consider it a top priority, but have no formal method for safety planning. In a broad sense, transit agencies approach safety planning in two ways: on a specified project level and in response to an identified safety issue. On the project level, agencies consider all aspects of safety once the project has begun. Safety is a fundamental part of project planning, design, and implementation. For example, if a transit system is planning to construct a new transit center, careful consideration will be given to factors such as (1) the layout, to minimize pedestrian crashes, and (2) the security design, to include lighting and possible police patrolling. New projects are developed with safety in mind, not with safety as the sole purpose.
There is one exception to this "project level" approach where safety is considered as a result of the project. This occurs when agencies design a project in response to identified safety concerns including high-incident locations, unsafe pedestrian facilities, or dangerous driver behavior. For example, the Three County Transportation Authority (Tri-Met), the transit provider for the Portland, Oregon, area, has identified certain bus stops as high-incident locations and is mapping the city's pedestrian environment to transit accessibility. Tri-Met's goal is to reduce incidents at these bus stops, thereby enhancing the safety of the bus system. Most agencies maintain some mechanism for recording crash information, some more formal than others. The larger agencies have elaborate systems for tracking accidents of all scales, from broken mirrors to crashes resulting in fatalities. Agencies with the resources to do so will analyze crash data to identify consistent incident locations and trends, and use this information to develop countermeasures and fund projects based on these safety improvements.
Aside from these two distinct methods, transit agencies address safety and security through indirect measures such as driver training, designation of a safety officer, and implementation of bus transit system safety program plans. Transit agencies must consider safety and security concerns beyond transit vehicle crashes. They must also consider access issues that affect transit safety such as safe pedestrian crossings and transit stop locations. They must also address security issues such as security cameras in transit vehicles and at transit stations, traveler information, and emergency activations. The American Public Transportation Association (APTA) has created a manual for the development of a Bus Transit System Safety Program Plan. These plans address items such as accident response and review, management safety roles and responsibilities, and emergency management procedures. APTA has implemented a Safety Management Audit Program to assist transit agencies in developing system safety programs and to evaluate the program's effectiveness. Further, transit agencies are expected either to use 1 percent of urbanized area formula grant funds on transit security or to document why the funds were not used. Transit security includes agency fencing, lighting, bus and facility cameras, and transit police.
Safety Problems Unique to a Transit Agency
Particular crash problems are unique to a transit agency. Transit officials frequently mention the following incidents:
- Crash fraud: A private driver encourages an accident with a bus.
- Driver crash fraud: A few drivers have too many crashes, usually in order to gain access to worker's compensation.
- Jumper's claims: People who never were on a vehicle involved in a crash (the term comes from people who jumped on the bus after a crash).
- Malingering, symptom magnification, and enabling by doctors and attorneys.
Most transit agencies will aggressively fight such claims and have in-house legal representation, as well as external legal services under contract. Unfortunately, it is a dimension that most large transit agencies have to confront periodically.
Design Issues in Transit Safety
Transit agencies run bus systems and, for some, rail systems, where numerous design issues affect safety. Bus stop locations can improve or decrease safety and security, and care must be taken to ensure safety at these locations (16). Many transit agencies devote extensive resources to improving safety and security at these locations.
For example, Tri-Met of Portland has a top-down approach to bus stop design. It conducts a macro approach to determine the existing routes and transfer points, and then maps the bus stop locations and evaluates them for Americans with Disability Act standards. Typically, bus stop placement is project driven. Tri-Met's principal concerns are:
- Safety
- Accessibility
- Comfort
- Efficiency
- Obtaining right of way
Some stops are placed in unsafe locations, such as along a stretch of highway without control devices or on a traffic island. The transit agency has created several partnerships with local governments and businesses to improve the bus stop environment. Currently, with support from other jurisdictions and the MPO, Tri-Met is leading the effort to map the pedestrian environment, including all sidewalk and pedestrian access points in proximity to Tri-Met stops.
Problems have arisen in placing stops in the jurisdictions outside of city of Portland. Although bus stop information has not been linked to crash incidents, Tri-Met is trying to improve the visibility of stops by adopting consistent signage and placement. It is also trying to improve lighting at stops. Currently, the transit agency is working on the external lighting and is creating partnerships with businesses to provide internal lighting. An experiment is being conducted to put user-initiated strobe lights to inform drivers when passengers are waiting at a stop. Tri-Met is also trying to improve consistency in the layout of bus stops. Shelters sometimes vary by size and design/aesthetics.
Tri-Met places a high priority on pedestrian safety, and the approaches taken by traffic engineers cause conflicts. For example, Tri-Met may want to move a bus stop 15 feet from a crosswalk while the engineers want the bus stop to be as close to the crosswalk as possible to avoid traffic backup. Trade-offs and compromises must be negotiated.
References
(1.) Chatterjee, A., F.J. Wegmann, N.J. Fortey, and J.D. Everett. "Incorporating Safety and Security Issues in Urban Planning", Center for Transportation Research, The University of Tennessee, July, 2000.
(2.) Pietrucha, M.T. and P.M. Garvey. "Pennsylvania Road Safety Audit Pilot Program", Pennsylvania Transportation Institute, University Park, Pennsylvania, March 1999.
(3.) Horne, D.A. "Road Safety Audits: The Federal Highway Administration Perspective." Institute of Transportation Engineers, 1999.
(4.) Interview with members of Pennsylvania Department of Transportation, Bureau of Highway Safety & Traffic Engineering, November, 2000.
(5.) Tarko, A., S. Eranky, and K. Sinha, Methodological Considerations in the Development and Use of Crash Reduction Factors, Presented at the 77th Annual Meeting of the Transportation Research Board, Washington, D.C. 1998.
(6.) SEMCOG manual Southeast Michigan Council of Governments, SEMCOG Traffic Safety Manual, Second Edition, SEMCOG, Detroit, Michigan, 1997.
(7.) Garber, N.J. and L.A. Hoel, Traffic and Highway Engineering, Second Edition, PWS Publishing Company, Massachusett, 1997.
(8.) Arizona Local Government Safety Project Analysis Model, Final Report 504. Prepared by Jason Carey for the Arizona Department of Transportation, Phoenix, Arizona, in cooperation with U.S. Department of Transportation, Federal Highway Administration, June 2001.
(9). Liu, C.C. and H. Chen, Safety Resource Allocation Programs and Input Processor: Users Manual, Turner Fairbank Highway Research Center, Federal Highway Administration, McLean, Virginia, 1988.
(10.) Reference Manual: GradeDec 2000 (version 1.4). Federal Railroad Administration, U.S. Department of Transportation, Washington, DC
(11.) GradeDec 2000: Federal Railroad Administration's Highway-Rail Grade Crossing Evaluation Software (version 1.4). Federal Railroad Administration, U.S. Department of Transportation, Washington, DC.
(12.) Armstrong, C.S., Big Picture Thinking, New Roles and Strengthened Partnerships are Keys to OKI's Success, Association of Metropolitan Planning Organizations, Washington, D.C., 1995.
(13.) City of Syracuse Truck Route Study: Final Report. Syracuse Metropolitan Transportation Council, Syracuse, New York, May 2000.
(14.) Getting Older and Getting Around: Aging and Mobility in the Delaware Valley. DVRPC, December 1999.
(15.) Steiner, R.L. and L.B. Crider, "Safe Ways to School: Combining Resources at the State, County, and Local Level to Improve Safety to Schools." Presented at the 78th Annual Meeting of the Transportation Research Board, January 1999, Washington, D.C.
(16.) Levine, Ned, Martin Wachs and Elham Shirazi, "Crime at Bus Stops: A Study of Environmental Factors". Journal of Architectural and Planning Research. 3 (4), 1986, pp.339-361.
