A critical review study was undertaken of the highway spot improvement program. Technical, administrative, operational, and economic factors affecting the program were examined with the goal of determining modifications of research activities to improve or support the program. A literature review was conducted and visits made to the bureau of public roads, selected states, and the American association of the state highway officials to determine: (1) what federal and state legislative and executive actions had authorized or directed the spot improvement program, (2) what engineering design criteria or what research has been employed to guide the program, (3) how the program was being conducted by various states, (4) what administrative, economic, engineering, and political problems were involved, (5) what progress was being made in improving highway safety through this program, and (6) what contributions the program had made toward reducing highway automobile accidents. Spot improvement programs in different states were found to vary considerably in scope, standards, and progress obtained. The methodologies of implementing and justifying a spot improvement program are discussed and areas for research and development identified. The vast economic implications of spot improvements are indicated. The study reveals that, in addition to inadequate accident-reporting systems, there is a dearth of knowledge regarding appropriate benefit-cost analyses and desired ultimate goals in highway design standards, both for safety and capacity. /Author/.
Abstract