NTL Record

Title National Traffic Speeds Survey II: 2009
Record ID 45706
Personal Name
Creator
Huey, R.; De Leonardis, Doreen; Freedman, M.
Corporate Creator Westat, Inc.
Corporate
Contributor
United States. Department of Transportation. National Highway Traffic Safety Administration. Office of Behavioral Safety Research
Publisher United States. National Highway Traffic Safety Administration
Publication Date 20120700
Language English
Abstract A field survey was conducted during spring and summer 2009 as a longitudinal repetition to a similar effort undertaken in 2007. The goal was to measure travel speeds and prepare nationally representative speed estimates for all types of motor vehicles on freeways, arterial highways, and collector roads across the United States. Over 10 million vehicle speeds were measured at 627 sites included in the geographic cluster sample of 20 primary sampling units (PSUs). Each PSU was a city, county, or group of two or three counties representing combinations of regions of the United States, level of urbanization, and type of topography (flat, hilly, mountainous). Speeds were acquired on randomly drawn road segments on limited access highways, major and minor arterial roads, and collector roads. Speed measurement sites were selected in road segments with low, medium, or high degrees of horizontal and vertical curvature or gradient. Overall, speeds of free-flow traffic on freeways averaged 70.5 mph and were approximately 17 mph higher than on major arterials, which at 53.3 mph were in turn about 6 mph higher than the mean speed of 47.0 mph on minor arterials and collector roads. Most traffic exceeded the speed limits. Seventy-one percent of traffic on limited access roads and about 56% of traffic on arterials and collectors exceeded the speed limit. About 16% of traffic exceeded the speed limit by 10 mph or more on freeways, arterials, and collector roads. Speeds of passenger vehicle size classes were generally higher than for medium trucks.
Rosap ID dot:1914
Rosap URL https://rosap.ntl.bts.gov/view/dot/1914
TRT Terms Traffic speed; Speed and delay studies; Speed data; Traffic speed measurement; Traffic safety; Highway safety
General Subjects Speed-related crashes; Speed management; Driving speeds; Traffic safety; Speed measurement
Classification NTL - OPERATIONS AND TRAFFIC CONTROLS - OPERATIONS AND TRAFFIC CONTROLS;
NTL - PLANNING AND POLICY - Surveys;
NTL - SAFETY AND SECURITY - Speed Limits;
NTL - SAFETY AND SECURITY - Highway Safety;
NTL - SAFETY AND SECURITY - Accidents
Geographical
Coverage
United States
TRIS Online
Accession No
1447855
Contract Number DTNH22-06-D-00033; Task order 0001
Report Number DOT HS 811 638
Availability NHTSA - Behavioral Safety Research
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/45000/45700/45706/811638.pdf
Format PDF
Database NTL Digital Repository