research report

The Impacts of Infill Rail Transit Stations: Implications for the Shinn Station Proposal

Abstract

Infill rail transit stations are being implemented to improve access to transit as well as to encourage and support urban development and revitalization efforts.  The stations are relatively low-cost because they use existing tracks and equipment, but costs vary substantially depending on the complexity of the station design and its surroundings. Travel time savings can accrue to passengers using the infill station, but the added stop will increase time for some riders and may necessitate changes in equipment, schedule, or both.  Ridership at the infill station depends on the size of the area made more accessible as well as the amount of new development and intensified activity that occurs in its vicinity.  Findings from the literature and US examples are used together with a preliminary site assessment and interviews to identify the issues that would be raised by a proposed infill station linking multiple services in the San Francisco East Bay.   The concluding section summarizes factors that should be considered in evaluating the impacts of proposed infill stations and discusses the broader implications for regional planning.

research report

Meeting SB1 Transportation Systems Performance Goals

Abstract

This research project directly addresses the Caltrans policy question of “How to meet the SB 1 ten-year (2027) mandated preliminary performance outcomes for additional state highway investments?”  More specifically, the study focuses on performance outcome number 4: “Not less than 90 percent of the transportation management system units in good condition”. As part of this project, the research team evaluated the Caltrans performance-based methodology to achieve the 90% performance goal in addition to completing a review of relevant reports from the Federal Highway Administration (FHWA), state departments of transportation, and Caltrans. The research team also conducted multiple meetings, phone calls, and emails with Caltrans management. The research team found that the Caltrans Transportation Asset Management Plan, which governs its SB 1 implementation, follows Federal Highway Administration guidance and published best asset management practices. Further, Caltrans has a solid asset management plan in place to meet the SB 1 target. The research team also provides several recommendations including but not limited to: 1) Caltrans should continue working on defining deterioration rates or models for transportation management systems (TMS), 2) the state of being in “good condition” for transportation management systems must be more clearly defined, 3) Caltrans should continue monitoring innovations in asset management, and 4) Caltrans should consider conducting more pilots of performance-based ITS maintenance.

research report

Introducing an Intelligent Intersection

Publication Date

August 1, 2018

Author(s)

Aditya Medury, Alex Kurzhanskiy, Mengqiao Yu, Offer Grembek, Pravin Varaiya

Abstract

This project seeks to remove one important cause of intersection accidents: drivers, pedestrians, and cyclists make mistakes because they lack sufficient information about the movement of others as they proceed through an intersection. There is spatial and temporal uncertainty. This missing information can be supplied by an ‘intelligent intersection’. It describes the signal from all approaches; predicts when the signal phase will change; uses sensor data to determine which blind spots are occupied; and predicts red light violations before they occur. The intelligent intersection broadcasts this information via radio and can be received by a connected vehicle or indeed anyone in the intersection with a smartphone or Bluetooth device, so most intersection users will get this information. The objective of this research is to design intelligent intersection infrastructure and evaluate its performance in terms of safety and mobility benefits.

research report

Evaluating the Use of Zero-Emission Vehicles in Last Mile Deliveries

Abstract

While trucks may only represent a small share of the traffic in urban areas, they generate more than half of the overall emissions for specific contaminants (Jaller et al., 2016). One of the approaches to contend with such issues is to promote the use of new technologies and alternative fuel pathways. This work conducts an empirical assessment of the economic and driving patterns of trucks used for last-mile delivery given the increase in these vehicles serving even more densely populated areas (compared to the long-haul transport). The work concentrates on parcel deliveries, as they are typically used to transport the goods resulting from the rapidly growing e-commerce demand. The authors evaluate the performance by analyzing real driving data from parcel fleets (Walkowicz et al., 2014; Jaller et al., 2017a), and use the data to conduct life-cycle assessments (LCA) to estimate the various impacts. The contributions of the work are 1) comparison analyses between parcel delivery driving data with other delivery vocations to identify different freight patterns. The analyses show the differences and similarities between the driving patterns when using different drivetrains for a number of parcel delivery vocations. 2) Estimation of delivery tour length distributions (TLDs), and specific fuel consumption (SFC) for different drivetrains and vehicle classes. And, 3) estimate the total cost of ownership (TCO), including externalities, of different truck technologies under numerous scenarios that assume changes in fuel efficiency and incentives of certain drivetrains. Additional sensitivity analyses are conducted to identify the key parameters that affect the TCO. Among these, the analyses show the efficiency of purchases and use incentives for these technologies. The results can be extrapolated to a system-wide scope for similar vocations with common operational variables and the benefits and costs of transitioning to zero-emission technologies can be explored.

policy brief

Vision Zero's Enforcement Problem: Using Community Engagement to Craft Equitable Traffic Safety Strategies