Post-war planning is the theme of practically all recent engineering meetings. This Thirtieth Annual Purdue Road School is no exception. You have already heard some interesting discussions on highway post­ war planning. Other papers will be presented at the following ses­ sions dealing with this very timely subject. Engineers are generally agreed that considerable thought should be given to thi...

This study aimed to investigate the relative performance of two models (negative binomial (NB) model and two-component finite mixture of negative binomial models (FMNB-2)) in terms of developing crash modification factors (CMFs). Crash data on rural multilane divided highways in California and Texas were modeled with the two models, and crash modification functions (CMFunctions) were derived. T...

In order to achieve smooth autonomous driving in real-life urban and highway environments, a motion planner must generate trajectories that are locally smooth and responsive (reactive), and at the same time, far-sighted and intelligent (deliberative). Prior approaches achieved both planning qualities for full-speed-range operations at a high computational cost. Moreover, the planning formulatio...

A cross-sectional time series database of U.S. data on fatalities and injuries is analysed using a fixed effects negative binomial regression. Data from 50 states over 14 years is used to examine the effect of various highway improvements on both fatalities and injuries. These include the total lane miles of capacity, total average number of lanes by functional road category (interstates, arter...

This paper deals with a trajectory planning problem that we call the ‘highway problem’. It consists in planning a time-optimal trajectory for a mobile which is travelling in a structured workspace amidst moving obstacles and is subject to constraints on its velocity and acceleration. By structured workspace, we mean that there exists lanes characterized by one-dimensional curves along which the...

Mature infrastructures require proper maintenance treatments. Highway agencies often face with limited maintenance budget which may result a large backlogs of maintenance works in each year. The main objective of this research work is to develop a multi-objective optimization model to support the multi-year decision making process of the highway maintenance management in Thailand. Preventive ma...

The purpose of this study was to investigate traffic flow characteristics at off-ramp junctions in Iranian expressways. The study was conducted on the traffic behavior in isolated off-ramp vicinity of 6-lane expressways. The database consisted of traffic flow and traffic speed information extracted from videotapes. The relationship between diverging traffic flow in the right lane of expressway ...

My remarks on the subject of “How We Can Improve Our Highway Administration” will be confined to certain important areas where improvements can and must be effected if highway administra­ tion is to measure up to the responsibilities of today. To a large extent this discussion will be based upon observations and experience in Wis­ consin, where the highway department has gone through a period o...