Traffic and highway engineering 5th edition pdf download

The positive aspects of the highway mode, however, go hand in hand with numerous negative aspects, which include traffic congestion, crashes, pollution, and parking difficulties.

Traffic and transportation engineers are continually involved in determining ways to reduce these negative effects. The effective reduction of the negative impact of the highway mode of transportation at any location can be achieved only after adequate information is obtained to define the problem and the extent to which the problem has a negative impact on the highway system.

This information is obtained by conducting studies to collect and analyze the relevant data. These are generally referred to as traffic engineering studies. This chapter has presented the basic concepts of different traffic engineering studies: speed studies, volume studies, travel time and delay studies, and parking studies.

Spot speed studies are conducted to estimate the distribution of speeds of vehicles in a traffic stream at a particular location on a highway. This is done by recording the speeds of a sample of vehicles at the specified location. Speeds of vehicles along sections of highways also can be collected using advanced technologies like the probing of cell phones.

These data are used to obtain speed characteristics. These characteristics are the average speed, the median speed, the modal speed, the 85th percentile speed, the pace, and the standard deviation of the speed.

Important factors that should be considered in planning a speed study include the location for the study, time of day, duration of the study, and the minimum sample size necessary for the limit of acceptable error.

The data on vehicular volume can be used to determine the average daily traffic, average peak-hour volume, vehicle classification, and vehicle-miles of travel.

Volume data are usually collected manually or by using electronic or mechanical counters; video imaging also can be used. It should be noted, however, that traffic volume varies from hour to hour and from day to day.

It is therefore necessary to use expansion factors to adjust periodic counts to obtain representative hour, weekly, monthly, and annual volumes. A travel time study determines the amount of time required to travel from one point to another on a given route.

This information is used to determine the delay, which gives a good indication of the level of service on the study section. The methods used to conduct travel time and delay data can be grouped into two general categories: 1 those that require a test vehicle and 2 those that do not.

Parking studies are used to determine the demand for and supply of parking facilities in an area. A comprehensive parking study usually involves 1 inventory of existing parking facilities, 2 collection of data on parking accumulation, parking turnover and parking duration, 3 identification of parking generators, and 4 collection of information on parking demand. It should be emphasized here that no attempt has been made to present an in-depth discussion of any of these studies, as such a discussion is beyond the scope of this book.

However, enough material has been provided to introduce the reader to the subject so that he or she will be able to understand the more advanced literature on the subject. Your email address will not be published. Determine the toll to yield the highest revenue for demand and supply function in part a , and the associated demand and revenue.

Substitute the total cost function into the demand function and solve for V. Add 25 cents to the original cost function. Add 50 cents to the original cost function. Determine the new volume of vehicles wanting to cross this bridge. Substitute the new cost function into the demand function and solve for V. Assume toll rate at T. Since the revenue generated is the toll rate, T, time the volume, V, first solve for V with the new cost function. It is desired to increase the toll to a point where revenue will be maximized.

Write the expression for travel demand on the bridge. Substitute the above expressions into the revenue function and differentiate with respect to x, setting the derivative equal to zero. Now, substitute the new toll, x, into the demand function developed in part a.

Determine the total revenue with the new toll. First, solve for the revenue to be generated by the new toll. For practical purposes and traveler convenience, round the toll increase to 75 cents. Next, determine the resulting volume after the new toll increase. Simply substitute the new toll into the demand function above. The manufacturer uses a utility formula that rates each mode. Discuss at least two. Let Utruck be the dis utility function for the trucks and Urail the dis utility function for the railroad.

Reliability: Does the mode consistently operate on schedule? Convenience: Which mode can deliver the freight to a serviceable location?

Security: Which mode reduces the risk of pilfering. Rideability: Which mode provides the best ride for the product? In other words, which mode is less likely to cause damage to the product while in transit?

Three possibilities exist: air, rail, or auto. Determine the total cost initial cost plus time cost for each mode. Other factors to consider, other than costs, when selecting a mode to travel might include the following: personal comfort the modes have to offer, whether additional connections need to be made to reach the final destination, the level of stress that can be anticipated by traveling by that mode, or whether the reason for travel is for business or pleasure. The long-term viability of the fuel tax is affected by crude oil shortages, improved automobile efficiency, use of alternative energy sources, and shifts to public transportation.

Additionally, the availability of revenue is reduced by diversion of fuel taxes to support transit, ethanol, and government general funds. Several financing concepts, including road use metering, electronic toll collection, and value pricing, may help to offset ineffectiveness in the fuel tax as vehicles become more fuel-efficient.

Road use metering involves charging highway users according to consumption vehicle-miles traveled , similar to many utilities. Electronic tolling is a related concept that can be applied on toll roads. Value pricing involves payment for values of service rendered as a function of demand.

The secretary is also the chairperson of the Commonwealth Transportation Board, a 16 member policy board that functions as a board of directors to i oversee the construction of highways and make regulations governing the use of state highways, ii ensure compliance with transportation-related federal laws, iii collect transportation statistics, iv regulate the location of outdoor advertising, v oversee the administration of the Transportation Trust Fund, and vi generally oversee the operation of the Virginia Department of Transportation VDOT.

This includes the daily maintenance and repair, design and engineering of future road projects, and the long range planning based on future demand projections.

This organization has its central headquarters located in Richmond, Virginia, and nine other District offices strategically located in other areas of the state. These District offices employ individuals to maintain the roads and the right-of-way year round, which includes the mowing of grass in the summer and plowing snow in the winter. In addition to the roadways, VDOT is also responsible for all of the roadway signs, signals, and street lighting. The activities focus around the phase of transportation project development: planning, design, construction, operations, and maintenance.

Organizational structure supports these responsibilities. Department of Transportation website and identify the name and location of highways in your state that are included as part of the National Highway System. According to data, Virginia has approximately 3, miles of the NHS. In Urban areas, there are 1, miles of highways: miles of Interstates, miles of other Freeways and Expressways, miles of other Principal Arterials, 36 miles of Minor Arterials, 6 miles of Major Collectors, and 2 miles of Local roads.

This includes Interstates 64, 77, 81, 85, 95, and Principal Arterials and strategic connectors, such as U. What services do they provide? Charlottesville Transit Service: Provides local bus service to the residents of Charlottesville. United Airlines: Provides passenger airline service to several cities outside the state.

Norfolk Southern Corporation: Provides freight rail service throughout the eastern U. Close suggestions Search Search. User Settings. Skip carousel. Carousel Previous. Carousel Next. What is Scribd? Explore Ebooks. Bestsellers Editors' Picks All Ebooks.

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