A test installation of deep polymer impregnation was applied to an 8‐yr old, heavily traveled bridge deck in Bethlehem, Pennsylvania, in 1975. While no surface spalls existed, the chloride contents at the level of the top reinforcing mat exceeded the corrosion threshold values. The deep polymer impregnation process involved drying the concrete, impregnating it to a depth of 7.6–10.2 cm (3–4 in.) with a catalyzed acrylic monomer, and thermally polymerizing the monomer. Detailed field and laboratory examination after 9‐yr service revealed excellent performance from the impregnated concrete. Fracture planes and spalls were absent, whereas adjacent untreated areas were highly damaged. Surface wear was reduced by 65%. Half‐cell corrosion potentials revealed active reinforcement corrosion ouside the test area, but not within. Chloride contents were significantly lower in the test area. Pre‐existing corrosion cells within the test area were arrested.

The rates for breaking the bond between ice and road surfaces are measured as a function of temperature, type of road surface, and chemical application. Surfaces of asphalt, concrete, and brick give indistinguishable results. Chemicals used include sodium chloride, calcium chloride, urea, and calcium magnesium acetate (CMA). The results are analyzed in terms of the maximum areas undercut and the rates at which the areas are undercut. The areas for all chemicals can be correlated with arguments based on freezing point depression. The rates seem consistent with diffusion controlled melting.

During the past decade, many have questioned the propriety of the doctrine of sovereign immunity; numerous legal challenges and legislative changes have eroded the doctrine in most states. Following the 1979 modification of sovereign immunity legislation in Pennsylvania, the number of tort claims and lawsuits against the Department of Transportation has grown rapidly. In response, a study was made of the principal highway condition factors associated with tort legal actions and of the department's risk management. The results of that study are presented herein. Given the pervasiveness of the highway tort liability problem, many state transportation departments should benefit from the study findings and their implications.

The purpose of this study is to investigate some concepts regarding the role played by local airports in the economies of the regions they serve. The writers attempt to formulate a conceptual framework for the study of air‐ ports' economic development and/or growth effects on local economies. A small empirical survey is used to explore how such a framework could be further developed. The results of the empirical investigation of three small California airports suggest that local‐service airports in small communities have a rather precarious market situation, particularly if they happen to be in the general proximity of large cities served by major hub airports. Consequently, if a local airport is to be a successful economic venture and a rational investment by government, a geographical location that ensures independence from a major hub appears to be essential. In addition, since economic impacts of an airport are indeed a function of the type and amount of traffic it serves, this geographical hub independence may enable an airport to capture more local demand and, in turn, perhaps generate measurable economic impacts.

This paper reviews current knowledge of the three components of pavement contact pressure developed by a free‐rolling tire. A finite element tire model employed to calculate tire‐pavement contact pressure is described. These pressure distributions were used as pavement surface load input data for a pavement model (ILLIPAVE). The ILLIPAVE program utilizes a nonuniform tire contact pressure distribution in calculating the strains in a flexible pavement on a granular base. Results from the tire study indicate that, for a 10.00‐20 bias‐ply truck tire, the highest pressure in the tire‐pavement contact region is about two times the inflation pressure, for the 517‐kPa and 862‐kPa (75‐ and 125‐psi) inflation pressures considered. The analytical studies on flexible pavements were conducted primarily on thin pavements, since the effects of tire pressure are most pronounced in thinner sections. The results indicate that these truck tire contact pressures produce high tensile strains at the bottom of the pavement. It is found that nonuniform pavement contact pressure, as produced by a real tire, causes significantly higher pavement strains than those calculated with the conventional assumptions of uniform contact pressure.

A variety of innovative financing techniques for highway and transit is reviewed. With federal support diminishing and transportation needs growing, agencies are seeking new ways to fund transportation projects. The techniques discussed fall into the four broad categories: charges on benefiting properties; joint venture approaches; user charges; and marketing and merchandising approaches. Charges on benefiting properties recognize that there are specific beneficiaries who gain from transportation improvements. Techniques within this category include: connector fees, negotiated investments, special assessment, road corporations, tax increment financing, and impact requirements. Joint ventures with the private sector recognize that it is mutually advantageous for public and private sectors to cooperate on transportation projects and include the techniques of land/air rights leasing, donations for capital improvements, and cost sharing. User charges are intended as direct payments for services rendered and are classified as motor vehicle taxes and fees, tolls, commercial parking taxes, and taxes on motor fuels. Marketing and merchandising approaches include advertising and merchandising. None of the techniques is a panacea for transportation finance, but where appropriate conditions exist, they can be effectively used to finance the growing transportation needs of our nation.

The results of experiments testing the public use of automobiles in the United States are presented. The Purdue Mobility Enterprise system was a work‐based shared‐vehicle concept, where households used mini/micro‐class automobiles for normal daily travel, and full‐sized shared vehicles for less frequent but more demanding trips. Comparisons between a mobility enterprise system and more typical auto ownership schemes are presented with respect to transportation costs and vehicle utilization. An analysis of the key attributes for success of such a system and a review of a home‐based system (the STAR project) are also presented.

This technical note provides a definition for public-private partnerships in joint development and notes three different but equally legitimate public policy goals for joint development activities. Primary attention is given several principles that appear to be necessary ingredients for the successful implementation of a joint development project. Recommendations are given to guide the public partner when undertaking public-private joint development ventures. Among the recommendations made and the principles examined are the need for the public sector to view joint development as a major activity and the need for the public partner to behave like a full partner rather than as a passive partner. This includes active involvement in the design and development phases of the project.

The effect of vehicle characteristics on fuel consumption is calculated using a basic energy-related model of instantaneous fuel consumption and on-road second-by-second speed, acceleration, and grade data. By integrating the instantaneous model over observed on-road speed profiles, aggregate models have been derived with vehicle parameters explicit at all model levels. Using this approach, interpretation of the parameters of the well-known average travel speed model is possible. The constant term in this model is related to the fuel to provide tractive force to the vehicle and the coefficient of the reciprocal of average speed can be interpreted as the idle fuel consumption rate. The effects of engine capacity and mass on the parameters of the average travel speed model are discussed. This approach is then compared with the estimated effect of engine capacity on fuel consumption derived using the average travel speed model and official fuel consumption tests.