Roads/Highways

The assessment of Transit Signal Priority (TSP) impacts at traffic signals is typically based on simulation and field studies. There is a need for macroscopic procedures for analysis of TSP as part of the Highway Capacity Manual (HCM) analysis methodology for signalized intersections. This capability will allow prediction of TSP impacts (and related control strategies) at a planning and operations level without the complexity of simulation modeling. The paper presents a technique of estimating the average green times for each lane group, and modifications to the HCM formula for estimating...

The San Francisco–Oakland Bay Bridge is located in the heart of the San Francisco Bay Area in California and connects two of the largest cities in northern California over San Francisco Bay. In July 2010, the Bay Area Toll Authority (BATA) increased tolls on the San Francisco–Oakland Bay Bridge from a flat toll collected westbound only to weekday peak and off-peak tolls. BATA also instituted a carpool toll of $2.50 (previously carpools crossed for free) payable by FasTrak electronic toll collection tag only. With floating-car data provided by BATA, the change in travel time for the I-80, I...

We propose a methodology for identifying queue spillovers in city street networks with signalized intersections using data from conventional surveillance systems, such as counts and occupancy from loop detectors. The key idea of the proposed methodology is that when spillovers from a downstream link block vehicle departures from the upstream signal line, queues discharge at rates smaller than the saturation flow. The application of the methodology on an arterial site and the comparison with field data show that it consistently identifies spillovers in urban networks with signal-controlled...

The I-880 field experiment has produced one of the largest data bases on incidents and freeway traffic-flow characteristics ever compiled. Field data on incidents were collected through observations of probe-vehicle drivers before and after the implementation of freeway service patrols (FSPs) over a freeway section. Supplementary information was collected from the California Highway Patrol's computer-aided dispatch system, FSPs, and tow-truck company logs. The incident patterns are described and the major factors affecting incident frequency and duration are identified. FSPs significantly...