Taylor W P Lochrane

Using a Living Laboratory to Support Transportation Research for a Freeway Work Zone

This paper presents the concept of a living laboratory (LL) and how it is applied to transportation operations research through a case study. This case study focuses on calibrating the Wiedemann car-following model parameters specific to freeway work zones. Applying the concept of an LL enables the experimental platform to be in a natural real-world environment. The design of this LL included the development of an instrumented research vehicle (IRV) to capture the natural car-following response of a driver when entering and passing through a freeway work zone. The development of a connected mobile traffic sensing (CMTS) system, which included state-of-the-art intelligent transportation systems (ITS) technologies, supports the LL environment by providing the connectivity, interoperability, and data processing of the natural, real-life setting. The IRV and CMTS system are tools designed based on the research objective to support the concept of an LL which facilitates the experimental environment to capture and calibrate natural driver behavior. This case study shows the application of an LL specific to operations research providing an experimental platform for evaluating the operational performance of a roadway in a real-time, connected, and collaborative natural environment.

Modeling Driver Behavior in Work and Nonwork Zones: Multidimensional Psychophysical Car-Following Framework

A new multidimensional framework for modeling car following on the basis of statistical evaluation of driver behavior in work and non-work zones is presented. The models developed as part of this multidimensional framework use psychophysical concepts for car following that are close in character to the Wiedemann model used in popular traffic simulation software such as VISSIM. The authors hypothesized that with an instrumented research vehicle (IRV) in a living laboratory (LL) along a roadway, the parameters of models developed from the multidimensional framework could be derived statistically and calibrated for driver behavior in work zones. This hypothesis was validated with data collected from a group of 64 random participants who drove the IRV through an LL set up along a work zone on I-95 near Washington, D.C. For this validation, the IRV was equipped with sensors, including radar, and an onboard data collection system to record the vehicle performance. One of the limitations of current car-following models is that they account for only one overall behavioral condition. This study demonstrated that there are four different categories of car-following behavior models, each with different parameter distributions: the four categories are divided by traffic condition (congested versus non congested) and by roadway condition (work versus nonwork zone). Calibrated threshold values for each of these four categories are presented. Furthermore, this new framework for modeling car-following behavior is described in a multidimensional setting and can be used to enhance vehicle behavior in microsimulation models.

User-Friendly Benefit–Cost Estimation Tool for Traffic Incident Management Programs

Traffic incidents contribute significantly to deterioration in the level of service on freeways and arterials. Traffic incident management (TIM) programs have been introduced worldwide to mitigate the effects of traffic incidents on safety and roadway performance. These programs support quick incident response and thereby shorten incident duration, and control traffic demand around the incident scene. Some TIM programs can be costly to taxpayers. Thus, it is important to be able to evaluate benefits and determine associated returns on investment. Although benefit–cost (B/C) estimation studies have been conducted for numerous Safety Service Patrol programs, these studies use a wide range of estimation methods and monetary equivalent conversion factors. Consequently, the resulting B/C ratio estimates vary widely and have been shown to be sensitive to these choices. Moreover, these studies can be quite costly. Therefore, this paper is aimed at developing a user-friendly TIM-BC tool with a standardized method that can be universally and equitably used in such a B/C ratio estimation for TIM programs, essential to creating consistency and, therefore, greater confidence in the validity of estimation results. With access to the method in the form of a simple-to-use, less data-intensive tool, TIM programs and taxpayers alike can benefit from cost-effective evaluations. A New York State case study compared the effectiveness of implementing three selected TIM strategies, namely, Safety Service Patrol, driver removal laws, and dispatch colocation. The case study also helps in understanding the need for a standardized B/C ratio estimation tool and the effectiveness of the developed TIM-BC tool.