Highway design and operational suitability is largely based on the ability of drivers to use the roads safely and efficiently. Designers and highway and traffic engineers should have an appreciation of basic human factor considerations to provide suitable designs, maintain proper operations, and upgrade substandard roads. Key Positive Guidance principles leading to design and operational suitability include: Driver Reception and Use of Information, based on an “information‐decision‐action” driving task model; Information Handling Characteristics, predicated on driver “single channel” attributes; Decision Sight Distance to provide a margin for error in a cluttered environment; Driver Expectancy and Design Consistency in design and operations, and Driver Error reduction through proper design and operational procedures and information presentation. Given the present situation of limited resources, the highest pay‐off for the application of human factor considerations is to enhance the operations and safety of existing arterials, city streets, and rural roads.

Construction, maintenance, and operation of transportation infrastructure and vehicles represent a substantial energy investment. This indirect energy consumption per vehicle kilometer was estimated for auto, bus, and rail transit through an energy investment analysis. Initially, total construction and manufacturing energy were converted to annual energy by assuming a service life. The annual operations and maintenance energy were added to this amount to obtain the total annual facility energy consumed. The total energy per vehicle kilometer was then derived based on observed levels of traffic on each type of road and transit facility. Finally, the vehicle manufacturing energy was added to obtain a grand total estimate of the megajoules per vehicle kilometer. The resulting modal energy estimates in megajoules per vehicle kilometer were: Freeways, 1.368; arterial streets, 1.525; 2‐lane roads, 1.582; trolleybuses, 1.503; diesel buses, 1.568; at‐grade street car, 10.778; commuter rail, 14.154, and subway, 22.636. The indirect energy associated with rail transit facilities is sizable both in absolute terms, and as a proportion of the total energy consumed. It should be carefully estimated and must be included in modal energy intensity analysis.

Compressive forces may be induced in pipelines by the restraint of axial extensions due to temperature changes or other causes. These forces may cause vertical or lateral buckling of the pipeline. These two buckling modes, which both involve an overall column‐type response without gross distortion of the pipeline cross‐section, are analyzed on the basis of related work on railroad track. For normal coefficients of friction, the lateral mode occurs at a lower axial load than the vertical mode and is dominant in pipelines unless the line is trenched or buried. The theoretical solutions are illustrated by numerical results for a typical pipeline and some design implications reviewed.

The four principal directions of buried pipeline restraint are vertical‐ uplift, horizontal‐lateral, vertical‐bearing, and longitudinal‐axial. The remaining soil restraint categories out‐of‐plane with the primary directions are associated with oblique pipe motion. An analogy is made between restraint of buried inclined anchor plates and restraint of pipelines subjected to motion in the horizontal‐vertical (lateral‐uplift) direction. The behavior of soil restraint for inclined anchors is extended to buried circular pipes. Tentative design procedures are proposed to develop bilinear load‐displacement relationships for soil restraint of pipelines subjected to horizontal‐vertical motion.

This paper describes and evaluates the various methods used in the analysis and design of buried pipelines under vehicular crossings extracted from a vast number of literature. It was found that a unified treatment of the subject is currently not available and additional work is required. The study shows that there are sufficient data and technical information that can be integrated to produce sound design. Theoretical as well as empirical formulas are scrutinized and incorporated in their appropriate places. Design examples are presented, complete with the detail calculations. Where applicable nomographs and graphs are adapted as design aids. A brief review of the current safety codes pertaining to natural gas pipeline design is also presented.

Addition of small quantities of polymers to water results in a considerable reduction of drag in pipes. Polyox WSR‐301, one of the most effective drag reducing polymers, appears to be quite effective at concentrations of only a few ppm. Studies with this polymer indicate that drag reduction depends on several factors among which pipe size is predominant. The onset of drag reduction for Polyox WSR‐301 solutions appears to occur at a wall shear stress of $0.2N/m^2\text{.}$ The present study with flow of Polyox WSR‐301 solutions in capillary tubes indicates a complete elimination of the abrupt laminar to turbulent transition. Instead, a gradual deviation from the extension of laminar friction line is experienced until the polymer molecules are degraded under high rates of shear. Based on the onset parameter, explanations are offered for some aspects of the problem.

Experimental data on the axial, bending and torsional behavior of ductile cast iron pipes with rubber gasket joints is presented. Analytical expressions are provided which predict the resistance mechanisms and behavior of the joints. The bending mechanism is found to be quite different from the axial and torsional mechanism. By repeating the tests in a specially designed soil box, the effects of burial depths are determined. A joint stiffness matrix including axial, bending and torsional effects is provided. The slip behavior of the joint changes the stiffness values, however this occurence may be dealt with by using an appropriate flag system. To minimize axial compressional stresses and interlocking bending stresses at the joint, a minor geometrical change in the joint needs to be made. Joints with larger lip lengths provide more flexibility when subjected to axial compression or joint bending rotations.

In order to design flexible pavements employing the AASHO Interim Guide, one must know the layer coefficients of pavement materials. The results of a study to derive structural layer coefficients of several Mississippi pavement materials—surface mixture and base mixture of asphalt concrete, soilcement, and soil‐lime—are presented. Fatigue cracking is the criterion employed in deriving the structural layer coefficients. A model is developed to estimate fatigue life or performance or both of pavements treating traffic, material characteristics, and environmental effects as stochastic variables. Material characteristics that govern the pavement performance include resilient modulus and fatigue sensitivity. Although the inputs are probabilistic, the resulting model equation is deterministic and amenable to direct solution for the analysis/design of flexible pavements. Using this model with the stipulation that fatigue cracking in the wheel paths be less than 45%, the researcher establishes equivalent pavement cross sections. The layer equivalency of various materials is derived by comparing equivalent cross sections. The resulting layer coefficient values for base, soil‐cement, and soil‐lime are in agreement with those proposed by the AASHO Committee on Design.

The porosity of preformed fired soil aggregates for pores larger than 0.05 μm in radius (POR), which mainly determines the potential of bitumen absorption, cannot be successfully correlated to a single soil property. Multiple regression analysis shows a significant correlation of aggregate porosity POR with the following soil parameters: diameter corresponding to the median of particle size, illite content, specific surface and amorphous alumina content.

The use of alphalt pavements as railroad trackbeds has received considerable attention in recent years. However, very little is known about the design of such pavements for railroad use. A comparison between highway and railroad pavements shows that, due to the difference in loading conditions, the stresses and strains in railroad pavements are quite different from those in highway pavements. To prevent fatigue crackings, the horizontal tensile strain at the bottom of asphalt layer can be used as a design criterion for both pavements. To minimize permanent deformation, the vertical compressive stress at the top of subgrade should be used for the design of railroad pavements, instead of the vertical compressive strain as is most frequently used for the design of highway pavements. The use of full depth asphalt concrete is not as effective in railroad pavements as in highway pavements.