Speed Harmonization--Design Speed vs. Operating Speed

Jiang, Zhoutong; Jadaan, Khair; Ouyang, Yanfeng

Permalink

https://hdl.handle.net/2142/93364 Copy

Description

Title

Speed Harmonization--Design Speed vs. Operating Speed

Author(s)

• Jiang, Zhoutong
• Jadaan, Khair
• Ouyang, Yanfeng

Issue Date

2016-10

Keyword(s)

• safety impacts
• design speed
• operating speed
• geometric design
• crash rate
• benefit-cost analysis

Abstract

When the actual operating speed on the roads exceeds the design speed, which is common on rural highways, the roadway design may become problematic from a safety point of view. This report presents a new methodology that summarizes the relationship between design speed and operating speed, as well as the safety impacts of various geometric elements. A comprehensive literature review and a series of interviews with Illinois county engineers were conducted to summarize the currentroadway design and maintenance practices and their impacts on Illinois roadway safety. An integrated modeling framework that includes modules for (1) geometric design simulation, (2) operating speed‐profile prediction, and (3) crash rate prediction, is proposed. Based on this research, a benefit–cost analysis was also developed to quantify the economic benefits of various strategies for roadway safety improvement. All models were programmed into an Excel VBA‐based computer tool to facilitate decision making. The outcome of this project may be suitable for implementation in a wide range of application contexts.

Publisher

Illinois Center for Transportation/Illinois Dnepartment of Transportation

Series/Report Name or Number

ICT-16-021; FHWA-ICT-16-019

ISSN

0197-9191

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/93364

Sponsor(s)/Grant Number(s)

Illinois Department of Transportation, R27-SP30

Copyright and License Information

No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161.

Owning Collections