Overcoming Local Barriers to Regional Transportation: Understanding Transit System Fragmentation from an Institutionalist Framework [Policy Brief]

69A3551747134In this study we trace the development of a transit governance geodatabase for the 200 most populous metropolitan statistical areas in the United States. We use this database to describe thoroughly the metropolitan public transportation systems serving these regions, which include general-purpose local governments, multi-jurisdictional special-purpose governments, public and private transit agencies, and metropolitan planning organizations. From our data, we develop measures of the fragmentation and regionalization of the formal governance of these metropolitan public transportation systems. We discuss national patterns evident in these measures, and we use case studies of four metropolitan statistical areas\u2014two in California, one in Michigan, and one in Texas\u2014to illustrate in more detail the calculation of fragmentation and regionalization

Evaluation of Pavement Performance Using Remote Sensing Techniques

Infrastructure monitoring often requires interaction between the data collector and the traffic which leads to traffic delays as well as exposing the personnel to perilous conditions. Of late, different sensors like Light Detection and Ranging (LiDAR) and visible range cameras mounted on various platforms classified as terrestrial and aerial have been used to remotely inspect the infrastructure assets. Due to the advancement of these sensors, application of remote sensing techniques for monitoring infrastructure has gained lot of impetus in the past decade. The proposed research focused on monitoring the transportation infrastructure using terrestrial LiDAR and unmanned aerial vehicle-close range photogrammetry (UAV-CRP) technologies. The condition of the pavement infrastructure assets located in Dallas-Fort worth areas were monitored using these technologies. The soils in this area undergo swell-shrink behavior, causing premature failure of pavements resulting in several millions of dollars of expenditures annually for their rehabilitation works. The adopted procedures for the monitoring techniques and solutions can immediately benefit transportation agencies to easily obtain the valuable information in a safe manner

Integrating Transportation Management Companies (TMCs) and Public Transportation

Emerging technologies have given rise to Transportation Management Companies (TMCs), which deliver on-demand services via a customer-facing smartphone app. The expansion of wireless communication technology promises continued growth for ride-sourcing, and presents both challenges and opportunities in integrating these services into the transportation system (Middleton, 2010). Currently, the primary work linking on-demand service to public transportation focuses on the provision of both first- and last-mile trips (Clifton and Muhs, 2012). This study analyzes an expanded role for integrating TMCs into public transit linking the public and private sectors and providing greater accessibility through increased connectivity and coordinated service delivery. This integration requires a framework that facilitates and supports a public-private partnership. The authors examine the potential impact of this integration on transit services in an American context. Selected benefits include enhanced transit ridership, expanded access to employment, cost savings, and new revenue opportunities for transit agencies and private TMCs. This project examines the benefits of on-demand ride service from three aspects: 1) The extent that on-demand TMC services influence job access, 2) How this job accessibility varies spatially across different populations, and 3) How the cost-effectiveness of TMC services compares to traditional transit and what funding mechanisms might improve synergies between the two. This study focuses on the City of Chicago, and explores the impact of TMCs on accessibility to jobs and other amenities. With assumptions about average wait time of TMCs ranging from 1 to 12 minutes, the results of different scenarios suggest that TMC availability and trip lengths that TMCs can be used are the two more dominating factors influencing the extent to which accessibility can be improved. The accessibility improvement is most significant for areas with lowest existing accessibility and has no obvious difference across different population subgroups. Lastly, policy implications and potential funding and financing strategies of realizing the accessibility and equity benefits of integrating TMCs with transit are discussed

When and Where Are Dedicated Lanes Needed under Mixed Traffic of Automated and Non-automated Vehicles for Optimal System Level Benefits?

Automated vehicle (AV) technology is rapidly moving towards reality and will be mature within the next decade. However, the physical, institutional, and legal infrastructure for enabling widespread adoption of this technology is still lagging significantly. The focus of this research is on developing a decision framework for optimal upgrading of the road network for mixed AV and conventional (NAV) traffic. Given that AVs will undoubtedly share a large segment of the current road network with conventional traffic for the foreseeable future, how the network can be retrofitted to optimize the flow of all traffic is a critical issue. Of interest are questions regarding when and where the provision of dedicated lanes for AVs can offer benefits for all traffic, and at what level of AV adoption this investment becomes cost-effective. Answers to these questions are critical for planning the future transportation system. We use the term autonomous vehicle to indicate that they can not only drive without human interference using sensing technology but can also communicate with other vehicles and road infrastructure. While the technology is progressing rapidly, planning infrastructure investments and enhancements to optimally harness the benefits of AV technology capabilities merits serious attention. Specifically, the use of dedicated lanes to accommodate AVs so that they may platoon is an important consideration from a policy as well as planning perspective. The proposed study investigates this issue to determine when and where dedicated AV lanes would provide the maximum benefit to all traffic and make such infrastructure investments cost effective

A Multi-asset Transportation Infrastructure Asset Management Framework and Modeling for Local Governments

CTEDD 017-03Local governments (LGs) in the United States are managing 3/4 of 4 billion miles of roadway and more than 1/2 of nearly 600,000 bridges, which are critical transportation infrastructure assets that support the mobility, economy, and homeland security on both the local and national levels. To maintain the aging infrastructure in a state of good repair under shrinking budgets, LGs must adopt a systematic approach to conduct cost-effective maintenance, rehabilitation, and reconstruction (MR&R) instead of relying on subjective individual knowledge and experience. As a result, benefit from the scarce transportation budget could be maximized; and accountability could be demonstrated to the stakeholders

The missing link between place and productivity? The impact of transit-oriented development on the knowledge and creative economy

Emerging research suggests that planners and policy makers should explore the expanded role Transit-Oriented Development (TOD) plays in promoting innovation and economic growth. TOD station characteristics including accessibility, walkability, density, and mixed uses may create environments beneficial for creative and knowledge industries. However, the evidence linking place to productivity, as measured by firm sales volume is lacking. Using cluster analysis and Propensity Score Matching for national-level data, this research tests these relationships. Findings indicate that firms located in dense, mixed use, and walkable TODs with higher levels of activity experience increased sales. Hence, TOD and knowledge-based economic development strategies should be planned in tandem to maximize outcomes

The relationship between municipal highway expenditures and sociodemographic status: Are safety investments equitably distributed?

Different population groups have varying transportation needs based on their region type, socio‐economic, and socio‐demographic characteristics. Yet, municipal highway funding allocation methods do not typically consider these differences. Throughout the United States, municipal highway funding allocation is based upon fixed formulas that often only account for highway mileage and/or population size rather than equal benefits and funding outcomes across different population groups. This potentially creates an inequitable funding allocation process leading to safety and accessibility disparities between different population groups. This research investigates the extent to which the distribution of resources is not equal when evaluated by population group. Specifically, the relationship between municipal highway expenditures and poverty levels, population aged 65 years and older, race, and remoteness is investigated using data from the states of New York and Massachusetts. Using linear regression techniques, several models were developed that relate municipal highway expenditures with the socio‐economic and socio‐demographic characteristics of municipalities. The results revealed that there are clear municipal highway expenditure disparities between different population groups. Municipalities that have higher poverty levels experience a lower highway expenditure rate per local mile. Further, municipalities located in remote areas far from large metropolitan regions experience a disproportionately lower highway expenditure rate per local mile. Moreover, the results of this study indicate the need to consider how funding methods can address social differences

Evaluation of Cost-Effective Alternative Designs for Rural Expressway Intersections

Despite numerous studies demonstrating the effectiveness of Restricted Crossing U-Turn (RCUT) intersection design, its implementation remains uneven and close to zero in some large states such as California. This research provides a comprehensive framework to estimate the operational and safety performance of future RCUT designs in California. The framework is demonstrated for five intersections located on high-speed rural expressways in California using VISSIM microsimulation models to measure operational performance for each intersection including the base condition with the existing Two-Way Stop-Controlled (TWSC) intersection and two RCUT designs. To evaluate future safety performance, the microsimulation models were further utilized to compile vehicle trajectory data to use with the Surrogate Safety Assessment Model (SSAM) to develop a surrogate measure-based approach to estimating future safety performance. Detailed Intersection Control Evaluation (ICE) studies found that the RCUT was cost-effective and the preferred alternative. This framework may be applied to the analysis of locations where a RCUT intersection may be appropriate. The framework demonstrated here may be used by agencies to estimate the future benefits of the first-time application of treatments that have been successful elsewhere. Based on simulation results, the proposed RCUT designs reduced or eliminated the more severe crossing conflicts

Assessing the Impact of Bicycle Infrastructure and Modal Shift on Traffic Operations and Safety Using Microsimulation

A transportation system designed to prioritize the mobility of automobiles cannot accommodate the growing number of road users. The Complete Streets policy plays a crucial part in transforming streets to accommodate multiple modes of transportation, especially active modes like biking and walking. Complete streets are referred to as streets designed for everyone and enable safety and mobility to all users. A strategy of complete streets transformation is to connect isolated complete street segments to form a complete network that improves active mobility and public transit ridership. This research assessed the impact of efficiently and equitably connecting and expanding the biking network using dedicated lanes on the safety and operation of the network in Atlanta, Georgia. These connections are aimed at increasing the multimodal use of the streets in midtown and downtown Atlanta and achieving the mobility and public health goals through the integration of various modes of travel. The evaluation was done by modeling a well-calibrated and validated network of Midtown and Downtown Atlanta in VISSIM using existing travel demand and traffic design conditions (i.e., the baseline or Scenario 0). A total of three different conditions: existing, proposed, and alternative conditions, were modeled to see the effectiveness of bike infrastructure design improvement and expansion. Three scenarios were then modeled as variations of modal demand of the different condition models. Scenarios modeled are based on input from the City and Community stakeholders. Using the trajectory data from microsimulation, the surrogate safety assessment model (SSAM) from FHWA was used to analyze the safety effect on the bike infrastructure improvement and expansion. Results of this study showed a positive impact of complete streets transformation on the streets of Midtown and Downtown Atlanta. These impacts are quantified in this thesis

Analysis of the Effects of Adaptive Ramp Metering on Measures of Efficiency with a Proposed Framework for Safety Evaluation

Adaptive ramp metering (ARM) is a widely popular intelligent transportation system (ITS) tool that boasts the ability to reduce congestion and streamline traffic flow during peak hour periods while maintaining a lower implementation cost than traditional methods such as freeway widening. This thesis explores the effectiveness of ARM implementation on an 18 mile segment of the Interstate 80 (I-80) corridor in the Bay Area residing in northern California. Smaller segments of this particular segment were analyzed to determine the effective length of ARM on efficiency at various lengths originating from a known bottleneck location. Efficiency values were also compared against a control segment of the Interstate 280 (I-280) in San Jose to provide a test site experiencing similar traffic congestion but without any ARM implementation. An Empirical Bayes analysis was conducted to provide the foundation of a safety evaluation of the ramp metering implementation and determine a counterfactual estimate of expected collisions had ARM implementation not occurred. It was found that the installation of the ramp meters did allow for some marginal increases in efficiency but may not be entirely associated with ARM implementation due to a variety of external factors as well as showing inconsistent behavior between analyzed segments. Regarding safety, the predictive model estimates 32.8 collisions to occur along a 0.5 mile segment within a three-year timeframe if ARM were not installed, which implies substantial improvements in safety conditions. However additional efficiency and safety data within the “after” period may be necessary to provide a more robust and conclusive evaluation as the ARM system is still relatively new