Land Use and Built Environment

In light of chronic funding shortfalls and waxing highway construction and maintenance demands, public private partnerships (PPPs) (often though not always in conjunction with road pricing) have been garnering increasing attention from government officials in the U.S. and abroad. Despite many strongly-held opinions on PPPs – both pro and con – systematic evaluations of their efficiency, effectiveness, equity, and feasibility are all too rare.This paper is the first part of a research project that aims to rectify this shortage of careful, evenhanded, and rigorous analyses of PPPs by drawing...

This report presents and describes 400 aviation accidents which occurred within five miles of an airport. Section 2 contains a description of the development of the database and a discussion of the criteria used in selecting accidents for the database. Section 3 provides a description of the database itself as well as a set of statistics that provide a comprehensive overview of the accidents. A set of aircraft accident contours developed from the accident data points is presented in section 4. The purpose of these contours is to provide a picture of the distribution of accidents over space...

The current lane change maneuver for vehicles in a platoon under the California PATH automated highway system (AHS) architecture is inefficient, because the follower has to split from the rest of the platoon before making a lane change. In this report, we propose to add a lane change within platoons maneuver that allows a follower to change lanes and be inserted into another platoon directly without splitting either platoon. This maneuver is performed by aligning and locking the longitudinal positions of the two platoons in adjacent lanes. The estimated improvement in the AHS utilization,...

This report addresses the problem of designing safe controllers for the hybrid system composed by the interaction of the regulation and coordination layers in the hierarchical California PATH Automated Highway System (AHS) architecture. Conditions to achieve safe platooning under normal mode of operation are investigated. The results that are obtained allow for the decoupling of the design and verification of the regulation and coordination layers in the PATH AHS architecture.