Download Free Optimal One Way Traffic Control Strategy For Under Saturated Two Land Highway Work Zone Operation Book in PDF and EPUB Free Download. You can read online Optimal One Way Traffic Control Strategy For Under Saturated Two Land Highway Work Zone Operation and write the review.

Lane closure is a common practice for two-lane highway work zones. To effectively control the open lane to serve both travel directions, it is necessary to implement a traffic control strategy. Due to lane closure, the roadway capacity will drop significantly. The remaining capacity will depend on work zone configurations, traffic parameters and traffic control strategy. This study develops a mathematical model calculating capacity and vehicle delay specifically for two-lane highway work zones with pre-timed signal control strategy. A VISSIM simulation model is developed and calibrated using field observed data to validate the mathematical model. After fine tuning the parameters, the mathematical model is able to make reasonably accurate delay estimates for both saturated and under-saturated traffic demands, with mean absolute prediction errors between 1% ~ 3%. Flagger control is incorporated in the VISSIM simulation model using a gap-out distance method. Field observations are used to validate the model outputs. The study then compared flagger control with fixed time signal control under multiple traffic conditions. Results show that at low traffic demands flagger control performs better than fixed time signal control. For the specific work zone site studied, flagger control is able to achieve approximately 10% ~ 20% lower vehicle delay. The developed models and simulation results can be applied to optimize two-lane highway lane-closure work zone management by reducing overall user delay while maintaining adequate roadway capacity. The optimized pre-timed signal control plan can reduce the user delay to a similar level as that of the actuated or flagger control method and thus can be used to avoid the human operation cost. Sensitivity analysis shows that traffic operators can increase the roadway capacity by reducing work zone length, increasing vehicle travel speed, and making unbalanced signal allocation based on actual traffic demands.
TRB's National Cooperative Highway Research Program (NCHRP) Report 672: Roundabouts: An Informational Guide - Second Edition explores the planning, design, construction, maintenance, and operation of roundabouts. The report also addresses issues that may be useful in helping to explain the trade-offs associated with roundabouts. This report updates the U.S. Federal Highway Administration's Roundabouts: An Informational Guide, based on experience gained in the United States since that guide was published in 2000.
A practice used during long-term construction activities on divided highways is to allow two-lane, two-way traffic operations (TLTWO) on one roadway while the other roadway is completely closed to traffic. Federal, state, and local officials have become increasingly concerned in recent years about safety problems in TLTWO work zones. This report presents the results of operational and accident studies of 36 construction sites employing either two-lane, two-way operations or lane closure traffic control. Project cost information for four TLTWO and ten lane closure sites was also analyzed. Results of the study were divided into four areas: evaluation of centerline treatments on the two-way roadway segment; design of temporary median crossover roadways; comparison of TLTWO and lane closure operations; and general results.
The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.