Transportation Planning Organizations Research Articles

INVESTIGATION OF INFLUENTIAL FACTORS FOR BICYCLE CRASHES USING A SPATIOTEMPORAL MODEL

Abstract. Despite the numerous potential advantages of indulging in bicycling, such as elevation of health and environment along with mitigation of congestion, the cyclists are a vulnerable group of commuters which is exposed to safety risks. This study aims to investigate the explanatory variables at transportation planning level which have a significant impact on the bicycle crashes. To account for the serial changes around the built environment, the linear time trend as well as time-varying coefficients are utilized for the covariates. These model modifications help account for the variations in the environment which may escape the incorporated variables due to lack of robustness in data. Also, to incorporate the interaction of roadway, demographic, and socioeconomic features within a Traffic Analysis Zone (TAZ), with the bicycle crashes of that area, a spatial correlation is integrated. This spatial correlation accounts for the spatially structured random effects which capture the unobserved heterogeneity and add towards building more comprehensive model with relatively precise estimates. Two different age groups, the student population in the TAZs, the presence of arterial roads and bike lanes, were observed to be statistically significant variables related with bicycle crashes. These observations will guide the transportation planning organizations which focus on the entity of TAZ while developing policies. The results of the current study establish a quantifies relationship between the significant factors and the crash count which will enable the planners to choose the most cost-efficient, yet most productive, factors which needs to be addressed for mitigation of crashes.

Impact of New Tolls on Existing Roadway Facilities: Hampton Roads, Virginia, Experience

The Midtown and Downtown Tunnels have been two of the most congested facilities in the Hampton Roads area of Virginia. Traffic queues nearly 4 mi long were daily occurrences at both facilities during peak travel periods. To relieve this congestion, construction began in 2012 of an additional two-lane tube at the Midtown Tunnel, along with rehabilitation of the Downtown Tunnel and the original Midtown Tunnel, and the addition of an extension to the Martin Luther King Freeway. To finance the project, whose completion is expected in 2018, toll collection began at the Midtown and Downtown Tunnels on February 1, 2014. The Hampton Roads Transportation Planning Organization (HRTPO) studied the impact of tolling on the regional transportation system by comparing the traffic and transit conditions before and after toll collection was implemented at the Midtown and Downtown Tunnels. This research will assist local decision makers as they determine whether tolls should be included as a funding source for candidate major highway projects. Further, the research will provide other planning agencies with information about the regional travel impacts of tolling, given that tolls were implemented on existing facilities before capacity improvements were completed. This study included an analysis of changes in traffic volumes, queues, delays, and transit conditions and highlighted a survey funded by the HRTPO to assess the public’s views of the project. Among the findings was that peak period delays decreased by 32% at four river-crossing corridors after tolls were implemented.

Uncertain Cost Estimates Influencing Priorities for Multimodal Transportation Corridors

Economic uncertainties have prompted transportation departments to consider cost-effective spending to reduce funding shortages. Although methods exist for identifying and prioritizing projects, there is need for analysis of long-range plans that consider stakeholder perspectives. This article compares two pairs of cost estimates: (a) modal agency cost estimates with (b) highway-only implementations and (c) regional Transportation Planning Organization (TPO) plans with (d) the state Department of Transportation (DOT) highway plan. This article develops methods to compare the perspectives of cost estimates for transportation improvements. The methods are adaptable to include both preliminary cost data and detailed life cycle cost data. The results aid in the prioritization of engineering and long-range planning efforts for projects that are expected to contribute to the goals of a variety of stakeholder investments. The methods support efforts for increasing accuracy and inclusion of life cycle costs into project estimates and employment of more sophisticated cost methodologies, such as cost-effectiveness and cost–benefit analysis.

Integrating the Military into the Metropolitan Transportation Planning Process

According to the TRB Military Transportation Committee, most U.S. metropolitan planning areas with military installations currently have a disconnect between Department of Defense military bases, metropolitan planning organizations (MPOs), departments of transportation, and local communities. The Hampton Roads (Virginia) Transportation Planning Organization (HRTPO), however, has a long-standing relationship with the military community and has taken steps to increase related efforts in recent years. HRTPO has advanced the cause of planning in Hampton Roads—and, by example, in the United States—through a coordinated approach to meeting the transportation needs of the military located in the Hampton Roads region. In response to military concerns about local traffic congestion and delays, the HRTPO board placed greater emphasis on military transportation planning in the region by endorsing annual military briefings by military representatives to the MPO board and by including a military needs study in its work program. The Hampton Roads Military Transportation Needs Study, an ongoing effort by HRTPO, is reportedly the first and only attempt of an MPO to identify solutions to the transportation needs of the local military. The purpose of this paper is to inform other metropolitan areas about the integration of the military into the transportation planning process in Hampton Roads and to provide a summary of key findings from the region's Military Transportation Needs Study. Other MPOs can apply the methods, results, successes, and lessons learned from Hampton Roads to their respective regions.

From Academia to Application

This paper presents an overview of a new architecture for travel demand forecasting models. The new hybrid accessibility-based models are neither traditional trip-based models nor standard activity-based simulation models. Instead, they are a blend of aggregate and disaggregate component models offering much of the sensitivity typical of activity-based models but with more modest development and application costs. This paper presents results from the first full application of the new model design. It documents the experience of the Knoxville (Tennessee) Regional Transportation Planning Organization from the data collection and visioning stage to the stage of investing time and resources to develop the new model. Ultimately, some basic comparisons are made between the new hybrid model and the previous trip-based model. Some key innovations in the new model design are highlighted, making special note of added sensitivity to planning and policy variables. The paper also reports findings related to the effects of residence location on travelers' willingness to travel and the effect of psychological barriers such as river crossings and county lines on stop location choice.

Anticipating Welfare Impacts via Travel Demand Forecasting Models

A great disparity exists between the direction of travel demand forecasting by researchers and the travel demand models used by transportation planning organizations. Activity-based models of travel demand have become increasingly studied in the academic realm, and significant advances have been made in recent years. However, travel demand forecasting tools used in practice have lagged and rely on traditional, aggregate four- or five-step approaches. One reason behind the divergence in methods is the lack of work that directly compares performance of the two approaches. This research provides such a comparison, with an emphasis on calculations of traveler welfare. A traditional, aggregate model and an activity-based microsimulation model of travel demand were developed in parallel by using the same data for Austin, Texas. The models were applied for a base scenario and for several policy scenarios to test model performance and sensitivity to inputs. The spatial distribution of traveler welfare implied by these scenarios illuminates a variety of key differences in the models’ performance and suggests that the activity-based model enjoys a greater sensitivity to inputs. Additional outputs demonstrate the level of segmentation that can be attained in model outputs using microsimulation methods. The comparative analysis of these two competing approaches to travel demand forecasting also offers some insight into the practical benefits of an activity-based approach.

Toll Demand Model for the Delaware Department of Transportation Travel Demand Model

As transportation providers across the nation face growing funding shortfalls, they are increasingly looking to tolling as an option to increase revenue. As toll revenue becomes a more important part of the funding for transportation programs, agencies are seeking to determine the potential impacts of more complex arrays of tolling options such as electronic toll collection and frequency-of-use discounts. The transportation planning organizations responsible for providing information to agencies are being expected to produce more reliable forecasts of traffic and revenue that directly reflect the subtleties of these tolling scenarios. To provide this information, the Delaware Department of Transportation (DelDOT) developed an improved toll demand model. This toll demand model was incorporated into the existing nested logit mode choice model. One thing that makes the new toll demand model unique is that it not only incorporates the toll–no-toll choice but also includes an E-ZPass ownership model used for cash–E-ZPass market segmentation. The model allows DelDOT to reduce the amount of “unquantifiable” attributes included in the mode choice bias constants. The model would be readily transferable to other areas that either do not currently have tolling or do not explicitly account for tolling in their existing models.

Assessing Progress: The State of Metropolitan Planning Organizations under ISTEA and TEA-21

The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and the ensuing Transportation Efficiency Act for the 21st Century (TEA-21) established a central role for Metropolitan Planning Organizations (MPOs) in regional transportation planning. In this new role, MPOs found themselves bringing together governmental and nongovernmental organizations representing the various transportation modalities in the planning process. At the same time, these MPOs assumed responsibilities for more effectively integrating transportation plans with other public policy arenas that affect and in turn are affected by transportation at the regional level. This paper reviews the progress that MPOs have made in achieving these goals. It concludes that there has been some progress in most areas specified in the ISTEA/TEA-21 legislation, however, the institutional contexts of MPOs substantially limits their effectiveness as regional transportation planning organizations.