Mobility problems being encountered in Orange County, California, are significant and are expected to become worse. In response, the Orange County transit district is pursuing a transit development strategy that involves the provision of exclusive preferential facilities for buses and high-occupancy vehicles (HOVs). In developing this transitway program, a detailed analysis of potential long-range use was made, focusing on the emerging major activity centres in Orange County. The required HOV and transit demand estimates were developed through a microcomputer-based estimation process that involved nine specific tasks; a spreadsheet program was used along with various basic programs. Journey-to-work travel data for 1980 from the census bureau urban transportation planning package were used as a base and expanded to the year 2010 by using adopted population and employment growth factors. Mode splits were determined on the basis of the degree of travel-time savings that trips would achieve by using the preferential facilities in the a.m. Peak hour versus mixed-flow freeways as well as origin and destination characteristics. The degree of increase in mode-split values for transit and HOVs was largely a function of corridor statistical trends from studies of before-and-after conditions on other priority projects nationwide. HOV trips were assigned by microcomputer to a network of preferential facilities using equations that specified the ranges of cells from the trip matrix that would pass through links in the network. The equations were applied to a master file of projected HOV trips to produce directional link and access-egress volumes.
Samenvatting