The role of the Chicago area transportation study (CATS) in a land-use transportation study carried out jointly with the northeast Illinois planning commission (NIPC) is described. The cats tested the adequacy of its 1962 transportation plan with respect to five separate and distinct land-use alternatives to develop several alternative plans and corresponding land-use and population projections for the northeast Illinois metropolitan area for the year 1990. These alternative projections were to be used as input for evaluation of the cats transportation plan. Evaluation was involved of the adequacy of cats' plans to serve four land-use plans and to determine which plan was best from a transportation viewpoint. Description is given of the conversion of land-use and socioeconomic data to travel demand. Distribution and assignment of traffic networks, and prepared traffic and economic evaluation of the results. The methodology and the models are briefly described. Test results lead to the following conclusions: (1) the cats transportation proposals would adequately serve any of the proposed four land-use plans within the cats area, (2) the finger plan was the best land-use plan from the point of view of transportation because it organized land uses so that trip lengths were shorter and had a generally higher quality of service in the networks, (3) the cats l-3 highway plan was demonstrated superior to an alternate plan devised for the finger plan by traffic analysis and by the marginal rate of return economic analysis, and (4) the alternative marginal plan did not provide marginal benefits to justify the additional capital costs. It is concluded that the statistics support cats expressway proposals. It appears that a well-conceived plan based on spacing principles will work under a variety of land-use configurations.
Abstract