Safety

Preliminary Findings for a Lane-Keeping and Collision-Warning Driver Interface for Snowplow Operations

Steinfeld, Aaron
Tan, Han-Shue
1999

This paper describes the development process and some preliminary findings for the human-machine interface (HMI) component of a system to aid snowplow operators. The HMI was developed though a series of driver task explorations and prototype tests. The HMI design has resulted in positive driver feedback and quick learning periods. Keywords Driver assist system Snowplow Lane keeping interface Collision warning interface Human factors - snowplow

A New Methodology for Evaluating Incident Detection Algorithms

Petty, Karl
Bickel, Peter J.
Kwon, Jaimyoung
Ostland, Michael
Rice, John
2000

We present a novel, off-line approach for evaluating incident detection algorithms. Previous evaluations have focused on determining the detection rate versus false alarm rate curve -- a process which we argue is inherently fraught with difficulties. Instead, we propose a cost-benefit analysis where cost mimics the real costs of implementing the algorithm and benefit is in terms of reduction in congestion. We argue that these quantities are of more practical interest than the traditional rates. Moreover, these costs, estimated on training data, can be used both as a mechanism to fine-tune...

Incident Dispatching, Clearance and Delay

Hall, Randolph
2000

This report models response times and delays for highway incidents, according for spacing between interchanges and the time penalty for changing directions, enabling a response vehicle to reach an incident on the opposite side of the highway. A fundamental question in dispatching incident crews is whether to send the closest vehicle that is currently available or to wait for another to become available that is even closer. Waiting for a closer one is advantageous because service time is effectively reduced, adding to capacity and providing stability at higher levels of utilization. But...

Studies of Vehicle Collisions-A Documentation of the Simulation Codes: SMAC (Simulation Model of Automobile Collisions) Update 1

Chan, Ching-Yao
1999

This document describes part of the work conducted under MOU252 and MOU324, related to the studies of vehicle collisions in vehicle-following operations. This working paper is a detailed documentation of a computer program that is the core element of the simulation tools for vehicle collision dynamics. The program, SMAC (Simulation Model of Automobile Collisions), and its PC-platform version EDSMAC have been used extensively in recent work at PATH to investigate the consequences of vehicle collisions and the effects of vehicle-following parameters on collisions. A copy of the source codes...

Assistive Devices and Services for the Disabled: Auditory Signage and the Accessible City for Blind or Vision-Impaired Travelers

Golledge, Reginald G.
Marston, James R.
Costanzo, C. Michael
1998

This project (MOU276) represents the first third of a longer project concerning making cities more accessible to some disabled groups by addressing some problems associated with the use of public transit. (The other two-thirds of the larger project is continued as MOU343). The disabled groups targeted in this project include the vision impaired or blind, those with low vision who have difficulty reading distant signs, those who are developmentally disabled, dyslexic, or otherwise print handicapped, those who do not read the English language, the illiterate, and small children. The blind or...

Relationships Among Urban Freeway Accidents, Traffic Flow, Weather and Lighting Conditions

Golob, Thomas F.
Recker, Wilfred W.
2001

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related to both the flow of traffic and weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object...

Safety and Efficiency Tradeoff Analysis for Automated Highway System: Part 3: Longitudinal Separation on AHS: A Trade-off Between Collision Probability/Severity and Capacity

Tsao, H.-S. Jacob
Hall, Randolph W.
1997

This report develops a probabilistic model for analyzing longitudinal collision/safety between an abruptly decelerating vehicle and its immediate follower on an Automated Highway System. The input parameters are the distance between the two vehicles, their common speed prior to the failure, the reaction delay of the following vehicle and a bivariate distribution for the two deceleration rates. The output includes the probability of a collision and the probability distribution of the relative speed at collision time. These safety consequences can be used to balance the desire to increase...

Evaluation Of Work Crew And Highway Hazard Conspicuity

Misener, Jim
1998

The report quantitatively addresses conspicuity of highway features, particularly in work zones, from the perspective of driver detection and driver decision making. The study focuses on evaluating the detection process, selecting and exercising human perception-acquisition models suitable for quick running and larger scale microsimulations to evaluate system effectiveness of pre-Automated Highway System (AHS) driver-assist systems. The report describes this process and provides a detection example of a driver-assist collision avoidance model.

The Design of a Controller for a Following Vehicle in an Emergency Lane Change Maneuver

Swaroop, D.
Yoon, Seok Min
1999

A lane change maneuver is one of the many appropriate responses to an emergency situation. The design of an Emergency Lane Change (ELC) maneu- ver for a platoon of two vehicles is considered in this paper. In response to the presence of a stationary or a slowly moving obstacle in the lane or any such emergency, the lead vehicle in the platoon designs an ELC trajectory on-line and broadcasts the trajectory curvature information in real time to its follower. The problem considered, in this paper, is the design of an integrated lateral and longitudinal controller that enables the follower to...

A Tool to Evaluate the Safety Effects of Changes in Freeway Traffic Flow

Golob, Thomas F.
Recker, Wilfred W.
Alvarez, Veronica M.
2003

This research involves the development of a tool that can be used to assess the changes in traffic safety tendencies that result from changes in traffic flow. The tool uses data from single inductive loop detectors, converting 30-second observations of volume and occupancy for multiple freeway lanes into traffic flow regimes. Each regime has a specific pattern of crash types, which were determined through nonlinear multivariate analyses of over 1,000 crashes on freeways in Southern California. These analyses revealed ways in which differences in variances in speeds and volumes across lanes...