User-Friendly Traffic Incident Management (TIM) Program Benefit-Cost Estimation Tool

Introduction

Traffic Incident Management (TIM) is a “systematic, planned, and coordinated effort to detect, respond to, and remove traffic incidents and restore traffic capacity as safely and quickly as possible.”⁽¹⁾ The National TIM Coalition (NTIMC) has published a set of objectives for TIM programs around the Nation. This National Unified Goal (NUG) includes three main objectives: (1) responder safety; (2) safe and quick clearance; and (3) prompt, reliable, interoperable communications.⁽²⁾ Practitioners may design or select the TIM strategies that make up their TIM program overall with these objectives in mind. In addition to supporting the NUG, TIM programs aim to reduce overall incident delays, minimize vehicle fuel costs and emissions, decrease the probability of secondary incidents, and maintain safety for the driving public.

TIM is a relatively inexpensive way to reduce congestion. Various TIM programs have been shown to have a high return on investment. Using a traffic simulation program, analysts determined that Maryland State Highway Administration’s Coordinated Highways Action Response Team (CHART) program reduced travel delays on major Maryland corridors by 32.43 million vehicle-hours in 2009, equating to a savings in delay, fuel, and emissions valued at more than $1 billion.⁽³⁾ The Traffic Incident Management Handbook confirms TIM effectiveness in reducing average incident duration to 22 minutes, which resulted in almost 300 fewer secondary crashes in Maryland in 2005.⁽⁴⁾ FHWA⁽¹⁾ also found that TIM programs reduce average incident duration by up to 65 percent, decrease the possibility of secondary crashes by 30–50 percent, and contribute to savings of 2,600 to 7,700 gallons of fuel per incident.

In addition to economic benefits, TIM programs have also helped improve collaboration among stakeholder agencies, increase safety for the driving public and responders, and reduce productivity impacts from traffic incidents. There is a need within the TIM discipline for accurate, reliable, and easy-to-use methodologies or tools to estimate the benefits and costs of TIM strategies. Many reasons for needing BC estimation tools are provided by Cambridge Systematics⁽⁵⁾ and the Whitehouse Group.⁽⁶⁾ The most notable reason is that the limited budgets and resources of local highway agencies require program leaders to be able to prove program benefits to offset (or exceed) the corresponding costs. Software tools not only help practitioners estimate the BC ratios for their programs, but also enable stakeholders to think critically about options to trim program operation costs or increase program efficiency. These BC estimation tools provide objective methods to address the safety, reliability, and security goals of an agency or program.

Currently, there are various software tools available to practitioners, each with a unique way of defining benefits and costs. Many of the tools available presently focus on operations or intelligent transportation systems (ITS) strategies and have limited applicability for TIM programs; in other words, they are broader and produce relatively rough estimates of BC ratios.^(7)(8)(9) Each of these programs requires a different amount and type of input data from the user, and the complexity and accuracy of program output often correlate to the scope of the required input.

A few studies, as documented by Chou, Miller-Hooks, and Promisel,⁽¹⁰⁾ developed their own unique approach with special assumptions to analyze one of the most popular TIM strategies—the safety service patrol (SSP)—for which BC ratios range from 2:1 to 36:1. While BC ratios of SSP are high, they are also extremely variable among different programs and among different evaluation tools. This wide range emphasizes a need for a single, consistent, and accurate BC estimation tool for assessing and comparing TIM strategies.

Previous studies by the University of Maryland produced a prototype tool for estimating benefits and costs of SSP programs.^(11)(12) This tool and its estimation methodology were developed through extensive research, literature review, data collection, simulation, statistical analysis, and model development. The tool only addressed SSP. In this current Federal Highway Administration (FHWA) study, the Leidos team along with the University of Maryland, enhanced the current SSP-BC tool and modified this tool to create a standardized simple-to-use TIM Benefit-Cost estimation tool for a wider class of TIM programs andstrategies. This effort has culminated in a robust software platform for a TIM-BC estimation tool, including open source code and necessary documentation.

This report documents the development of the user-friendly Web-based Traffic Incident Management Benefit-Cost (TIM-BC) tool to conduct BC estimations related to a wide range of TIM strategies. It supports the analysis of return on investments. The methodologies, referred to as Duration-based and Proportion-based approaches, are standardized so that the B/C ratio estimates are consistent and ensure confidence in the validity of the results. In addition, the TIM-BC tool applies to eight TIM strategies, identified by a project advisory committee, involving leading experts in the TIM community. These eight strategies include safety service patrols, driver removal laws, authority removal laws, shared quick clearance goals, preestablished towing service agreements, dispatch colocation, TIM Task Forces, and second Strategic Highway Research Program (SHRP2) training. The report also applies the methodologytool to a case study completed on the I–95 Corridor Coalition in New York that helps elucidate the need for standardized B/C ratio estimation and demonstrate the effectiveness of the developed TIM-BC tool.

The outline of this report is as follows. The next section describes findings from a TIM-related literature review. The third section illustrates methodologies of BC estimation for TIM strategies. A Web-based TIM-BC tool is introduced in the fourth section, which is followed by a discussion of a case study that examines the application of the TIM-BC tool for a segment of roadway in the greater New York City metropolitan area. Conclusions and recommendations from this project are presented in the final section.