Compatibility of Design Speed, Operating Speed, and Posted Speed

Fitzpatrick, Kay; Blaschke, Joseph D.; Shamburger, C. Brian; Krammes, Raymond A.; Fambro, Daniel B.

i

Compatibility of Design Speed, Operating Speed, and Posted Speed

1995-10-01
By Fitzpatrick, Kay ; Blaschke, Joseph D. ; Shamburger, C. Brian ; ...

File Language:

English

Details

Creators:

Fitzpatrick, Kay ; Blaschke, Joseph D. ; Shamburger, C. Brian ; Krammes, Raymond A. ; Fambro, Daniel B.
Corporate Creators:

Texas Transportation Institute. Texas A&M University
Corporate Contributors:

Texas. Dept. of Transportation. Research and Technology Transfer Office ; United States. Department of Transportation. Federal Highway Administration
Subject/TRT Terms:

85th Percentile Speed Posted Speed Arterial Highways Design Speed Operating Speed Suburban Arterials Traffic Speed
Publication/ Report Number:

FHW A/TX-95/1465-2F
Resource Type:

Tech Report
Geographical Coverage:

United States;Texas
Edition:

Final: September 1994 - August 1995
Corporate Publisher:

Texas Transportation Institute. Texas A&M University
Abstract:

Design speed is used in selecting the vertical and horizontal elements for new roadways while speed limits are based on a statistical analysis of individual vehicular speeds. At some locations, the posted speed limit based on an 85th percentile speed exceeds the roadway's design speed. This situation is a result of the fact that criteria used in highway design incorporate a significant factor of safety -- i.e., roadways are designed for near worst-case conditions. When posted speed exceeds design speed, however, liability concerns arise even though drivers can safely exceed the design speed. Research conducted in this project clearly indicated that DOT officials are concerned with the potential liability; however, only a few of the respondents to surveys and interviews actually experienced a lawsuit relevant to the design speed-posted speed issue. The respondents indicated that the primary liability concern rests with the current AASHTO definition of design speed. If the definition were changed to reflect its actual meaning, then liability concern would be reduced substantially.
Format:

PDF
Funding:

0-1465
Collection(s):

US Transportation Collection
Main Document Checksum:

urn:sha-512:2035163b66b2565ca5b216f4931c2c2ad8e034e870587652ef3945f9f68992c5a3c55a5c0a628b747c91aeaea30a0c5721a76fbf6ff0be63bd008f2d5b35b80b
Download URL:

https://rosap.ntl.bts.gov/view/dot/82853/dot_82853_DS1.pdf
File Type:

[PDF - 3.45 MB ]

File Language:

English

ON THIS PAGE

Details

ROSA P serves as an archival repository of USDOT-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by USDOT or funded partners. As a repository, ROSA P retains documents in their original published format to ensure public access to scientific information.