A select list of references pertaining to traffic operations is presented. The list contains 62 references including handbooks, manuals, conference proceedings, textbooks, and case studies that the committee considers useful sources of technical information for ASCE members involved with urban traffic management. While this list is not all‐inclusive, further sources can be found in the bibliographies of most of its entries.

The formulation of a mixed integer‐linear programming model to determine a minimum‐cost flexible pavement design is presented. The model identifies the number, type, and thicknesses of paving materials required to meet the structural strength requirements of the pavement system at a minimum initial cost to the highway agency. Policies regarding the designation of minimum and maximum layer thicknesses are accommodated in the model formulation, including the establishment of variable minimum and maximum thicknesses based on the underlying material. In addition, the structural layer coefficients are allowed to vary with the pavement configuration, including the number and type of constituent layers. The model can be used to calculate a marginal‐cost function which has applications in the selection of cost‐effective measures designed to strengthen the structural pavement capacity.

A method for identifying control subareas in traffic signal networks has been developed and tested with data from the Miami, Florida, business district. The procedure combines the use of cluster and discriminant analysis to group signalized intersections. Unlike existing procedures which use degrees of association between adjacent signals, the multivariate procedures used in this method allow for consideration of degrees of association among all signals in the original network. Model tests used the flow ratio for each intersection approach as the vector of intersection attributes. The resulting subareas were compact, well defined and slightly different for morning and midday traffic conditions. The procedure appears to have considerable utility in defining control subgroups in signal system design.

The mechanical effects of selected types of traffic on buried, high‐pressure steel pipe are examined. A section of the Colorado Interstate Gas pipeline across Fort Carson's Pinon Canyon Maneuver Site, which should be most susceptible to damage, is studied. The relationship between depth of cover and steel pipe deflection is clarified using field test results, with special emphasis on dynamic effects (impact factor). The results presented provide the technical basis for evaluating the feasibility of pipeline protection from anticipated traffic by earth cover.

Pipeline stresses due to loss of support caused by depressions or scour below submarine pipelines are analyzed. The sea floor on which the pipe is resting is idealized by Winkler medium. Bending in horizontal plane due to hydrodynamic loads is considered in the analysis and theoretical equations and general solutions are presented. Theoretical results for vertical deflections due to loss of support are compared with experimental results, and computer results are presented in nondimensional form for a wide range of parameters. It is concluded that the stresses due to hydrodynamic drag will be affecting the resultant stresses considerably and will need consideration in the analysis. The deflection and moment coefficients are found to be linearly proportional to the load coefficient. An illustrative example has also been worked out to show the use of design charts.

The introduction of inexpensive microprocessor‐based computer systems has given county engineers a valuable tool for manipulating, storing, and retrieving timely information. A research project funded by the State of Alabama Highway Department has demonstrated the utility of an integrated set of microcomputer programs to a typical county highway department. The microcomputer is well suited to tracking labor, equipment and materials expenditures, comparing actual and budgeted expenditures, and tabulating equipment ownership, repair and gasoline consumption expenditures.

The profile and clearance heights at seven bridges of the New Jersey approach roads to the George Washington Bridge needed upgrading. To do this, nondestructive test (NDT) techniques were carried out on the pavement surfaces to determine the subgrade properties under the existing pavement. The NDT dynamic load and the measured deflection basin were analyzed to calculate the subgrade parameters, the elastic modulus (E) the CBR, and the modulus of reaction (K). The testing and calculation of 100 points, under heavy traffic volume, were completed in four hours. The subgrade parameters were used to design the reconstructed new pavement structure for local environmental conditions and for 20‐yr projected traffic loading.

The benefits of pooling vehicles among routes that emanate from a common focus terminal are examined. In this strategy, trips are still scheduled, but vehicles are not assigned to specific trips. Instead, vehicles belonging to the pool serve all of the round trips leaving that terminal in a first in/first out sequence. Pooling improves schedule adherence, since in a pooled system a bus returning early can “cover” for a bus returning late. Pooling also facilitates interlining (sharing of buses among routes), which reduces the need for slack time. A procedure is developed for estimating schedule reliability. This procedure is applied to a set of 8 routes emanating from a Boston area terminal where it was found that with pooling the fleet size could be reduced by 11% while at the same time improving schedule adherence.

There has been little use of statistical analysis for evaluating the degree to which highway construction materials comply with nonstatistical specification requirements. The increased use of statistics offers potential benefits in the areas of project management and improved project quality. Using the standard deviation of a series of individual materials test results, an estimate of the percentage of material within specification limits can be made. Region 10 of the Federal Highway Administration has demonstrated the use of this analysis for evaluating specification compliance and for pinpointing points of change in materials characteristics for further investigation by identifying significant changes in standard deviation and quality level.

A development of color pavement in Korea is presented. An examination of pavement materials used, preparation of specimen, comparison tests between regular and colored mixture, mixing at asphalt plant, and placing colored mixtures in field is included. A synthetic resin binder with light yellow color was developed, and proved compatible for colored pavement through the several comparison tests: Marshall stability test, wheel tracking test, ravelling test, and accelerated weathering test. For the pigment, several different inorganic products were used: ${\mathrm{Fe}}_2{O}_3\left(\mathrm{IOR}\right)\text{,}$ ${\mathrm{Fe}}_2{O}_3\left(\mathrm{IOY}\right)\text{,}$ ${\mathrm{Cr}}_2{O}_3\text{,}$ and ultramarine blue. The mixing operation and paving method of color mixture were same as regular asphalt concrete mixture, but the quantity of pigment replaced that of mineral filler. After a successful trial placing, the mixture was placed in the plaza of Great Seoul Children Park and the sidewalk of new Banpo Bridge. The utilization of color pavement will provide better roadway environment and traffic safety, and will be accelerated by the beautification plan for 1986 Asian and 1988 World Olympic Games in Seoul.

The direct safety effects of increasing the number of large trucks in urban areas are explored. A simple theoretical model of the consequences of mixing trucks with cars is presented. The model, supported by recent detailed data from national in‐depth accident investigation programs, indicates that the physical difference of mass between the two types of vehicles necessarily leads to a larger number of fatalities unless there is a concomitant reduction in the probability of such collisions. A comparison of urban and rural truck accident experience shows that the most severe urban accidents occur on urban interstate roads. Therefore, traffic engineers will be challenged by the problems associated with an increased truck population and will need to continue developing ways of reducing the chances of contact between the two types of vehicles in traffic flow.