Details:

Alternative Title:
Effectiveness of traffic signs on local roads
Corporate Creators:
CTC & Associates LLC
Corporate Contributors:
Minnesota. Dept. of Transportation. Research Services Section
Subject/TRT Terms:
[+]
Local Roads Traffic Control Devices Traffic Safety Traffic Signs
Publication/ Report Number:
TRS 1002
Resource Type:
Tech Report
Geographical Coverage:
Minnesota
Corporate Publisher:
Minnesota. Dept. of Transportation. Research Services Section
Abstract:
There does not appear to be significant credible research demonstrating the outright ineffectiveness of particular

traffic warning signs. The research we identified provides support for opposing points of view: that traffic warning

signs have a minimal or neutral effect on safety, or, alternatively, that warning signs are effective at reducing crash rates and severity. National guidance recommends that traffic warning signs be employed based on engineering

studies and engineering judgment, and suggests that the excessive use of signs can reduce their effectiveness.

The MUTCD guidance on warning signs begins with the direction that “the use of warning signs shall be based on an engineering study or on engineering judgment.” It further indicates that “the use of warning signs should be kept

to a minimum as the unnecessary use of warning signs tends to breed disrespect for all signs.” That directive is not

followed by guidance or research indicating what types of signs are actually ineffective.

Traffic sign effectiveness appears to be more a matter of perception and opinion than of fact based on evidence. For

example, NCHRP Synthesis 186, Supplemental Advance Warning Devices (1993, page 1), found that “the majority of the devices encountered in this project were not evaluated by formal effectiveness studies, but are simply

perceived to be effective by the responding agency.” A study of the effectiveness of static warning signs by the

Institute of Transportation Engineers (“Static Warning Signs of Occasional Hazards: Do They Work?”) came to a

similar conclusion. In that study 18 percent of responding state transportation agencies thought the use of static warning signs for occasional hazards was effective, but 93 percent indicated that no studies had been done to

investigate the actual effectiveness of the signs.

On the other hand, Fred Ranck, FHWA safety and design engineer, indicated in an interview that warning signs have

proven safety benefits (see the National Research and Guidelines section on page 3).


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:75233252daa288026310a52ddf8b0bfaf854a3446a638afa0c3de9726a293026
Download URL:
https://rosap.ntl.bts.gov/view/dot/17894/dot_17894_DS1.pdf
File Type:

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