|M.Sc Student||Reisfeld Eran|
|Subject||Delay Analysis at Signalized Intersections and Development|
of Warrants for Interchanges on Rural Highways
|Department||Department of Civil and Environmental Engineering||Supervisors||Professor Abishai Polus|
|Professor Yoram Shiftan|
|Full Thesis text - in Hebrew|
Economical component has a major part in selection of highway infrastructure projects. This research focuses on calculating the economical warrants, for upgrading a signalized intersection to a diamond interchange on rural highways. This research concentrates on an isolated intersection in a rural highway.
During the research two major components were examined: first, the cost of stopping delays in a signal intersection and comparing stopping delays in the interchange's intersections and second, the cost of safety, shown as a reduction in the number of accidents (interchange vs. intersection). From these benefits, the maximal costs to invest in the interchange may be concluded.
Analysis of the safety component was done according to a model developed by Bonneson in 1993. By calculating the change in the number of accidents at intersection and interchange and using the value of average accident, the benefit of safety was calculated in terms of net present value for twenty years.
In order to analyze the delay component, the variation in hourly traffic flow during the day needs to be taken into account. The delay for each interval was calculated and transformed to the cost of delays using the value of time.
The main conclusions of this research are as follows:
· Economic justification for an interchange, would be achievable at traffic volumes, which are lower than capacity of the signal. Therefore, some of the researchers in the past preferred a benefit-cost ratio of two rather than one, in order to justify an interchange.
· This research emphasizes the importance of defining the value of time. A higher volume is needed to justify an interchange when a low value of time is used. When the value of time was low, the safety component became more important. It was shown that, the safety component is more important when there are lower volumes and when there are lower delays at the intersection.
· Increasing the interest rate, increases the minimal volume in the intersection, needed to justify an interchange.
· The major-minor roads volumes ratio showed that increasing the ratio (minor road volume vs. major road volume), decreases the warranting volume (that justifies an interchange) of the whole intersection.