Land Use and Built Environment

The California Department of Transportation, as part of their involvement in the California Hydrogen Highway initiative, is planning to construct a hydrogen station at their new maintenance facility in Sylmar, CA (Shop 7, at the junction of I-5 and I-405). This report was written to provide Caltrans information on the design and cost of various hydrogen station types. This information will be used to guide decision-making in choosing the station type and size to meet the anticipated hydrogen vehicle demand at their new facility.

There is increasing interest in building new high occupancy toll (HOT) lanes and in converting high occupancy vehicle (HOV) lanes with unused capacity to HOT lanes. Like HOV lanes, HOT lanes provide an incentive for travelers to use HOVs, but unlike HOV lanes, they can always be well utilized by varying the toll over the congested period, thus providing more congestion relief than an HOV lane with unused capacity. This report provides guidelines regarding the circumstances in which HOT, HOV, and mixed flow lanes are most appropriate. Using a queueing model combined with a mode choice model...

This is the most extensive empirical evaluation of the effectiveness of California’s HOV system based on data collected from traffic sensors. The evaluation leads to four major conclusions. (1) Since it operates as a single lane freeway, an HOV lane suffers a 20 % capacity loss compared with multi-lane freeways. (2) HOV lanes are either under-utilized or suffer degraded operations. (3) HOV lanes do not measurably increase car-pooling. (4) HOV lanes do not reduce overall congestion in a reasonably well-managed system.

District 10 of the California Department of Transportation (Caltrans) encompasses an area of seasonal fog and dust-related visibility problems that have been the cause of numerous multi-car traffic collisions, many fatal. In 1990, motivated by the expansion of State Route 120 (SR 120) connecting Interstate Highway 5 (I-5) and State Route 99 (SR 99), Caltrans proposed a sophisticated multi-sensor automated warning system as a means for reducing incidents in this high-traffic area. This proposal, and the significant development effort that followed, culminated in the implementation of Phase...