Citation

Pittman MA, Loutzenheiser RC. Highw. Res. Rec. 1973; 469: 65-74.

Copyright

(Copyright © 1973, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Accident investigations conducted on the freeway shoulder cause freeway congestion and delay to motorists. If the accidents are investigated off the freeway at a site concealed from motorists, congestion and delay will be reduced, and traffic flow will return to normal more rapidly. Sixteen accident investigation sites were designated along a 6-mile section of the gulf freeway in houston. Eight of the sites are located on city streets adjacent to the freeway; two are located on city streets under the freeway; and the other six are on unused space within the freeway right-of-way. Houston police officers began using the sites on july 12, 1971. Data were collected for 1 year through supplementary accident report forms that each investigating officer filled out. During the first year of operation, 851 accidents were reported in the study area, and the sites were used for 339 investigations (40 percent usage). In addition, another 176 investigations were conducted at other off-freeway locations (21 percent). Benefits in terms of delay saved from usage of the investigation sites and other off-freeway locations amounted to $203,000. Construction costs were prorated, and the annual cost and the maintenance costs were estimated at $8,000. For the first year of operation, the benefit-cost ratio was 28:1. Analysis showed that the sites under the freeway had a higher usage rate than those located on city streets.

Language: en

Keywords

HIGHWAY TRAFFIC CONTROL; HIGHWAY ACCIDENTS; HIGHWAY ENGINEERING