Citation

Telford ET. Highw. Res. Board bull. 1951; 35: 3-18.

Copyright

(Copyright © 1951, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The San Rafael freeway was constructed in 1939-40 to alleviate a serious bottleneck that had developed in San Rafael due to the increased volume of through traffic using the narrow city streets which were already taxed to capacity by measured local traffic. The viaduct structure was selected to carry the freeway through the more congested part of town, so as to allow a free passage of local traffic under the viaduct on existing city streets. A narrow median was used as a safety precaution to more effectively separate the opposing fast-moving traffic. The use of a narrow median was an economical expedient resulting in a saving in width of roadway, viaduct structure and right-of-way. The freeway has demonstrated its ability to carry a large amount of through traffic and at the same time provide safe ingress and egress for local traffic. The median has been efficient in preventing accidents involving opposing traffic as is evident by the absence of accidents of that nature. As there are no left turns permitted and therefore, no need for median storage lanes, a wider median would seem to be of no advantage.