01340940

Component

One intersection design that has been implemented for several years in Cairo, Egypt, is the unconventional Median U-Turn (MUT). In this paper, the operational performance of this design is analyzed and compared against baseline conventional four-leg intersections and conventional MUT designs with signalized and unsignalized crossovers. VISSIM was used to model and simulate the three designs under a wide range of balanced and unbalanced volume scenarios. Average intersection delay and overall capacity were used as the evaluation criteria. The performance of the unconventional MUT intersection was shown to be very poor in comparison to other designs. Few cases were identified when the unconventional MUT might outperform other designs. The overall capacity of the unconventional MUT intersection was lower than that of a conventional 4-leg intersection by about 27%. Meanwhile, the capacity of conventional MUT intersections with signalized and unsignalized crossovers was about 10% and 8% higher than that of the conventional intersection, respectively. To quantify the impact of increasing the percentage of left-turn traffic on the performance of the unconventional MUT design, two different splits of left-turn volumes were analyzed; 20% and 30% of the total approach volume. It was shown that increasing the left-turn percentage from 20% to 30% caused an insignificant reduction of intersection capacity of about 3.2%. Despite the poor operational performance, the unconventional MUT design is increasing in popularity among city officials in Cairo. Traffic regulations enforcement, reducing the manpower required to operate signalized intersection, and policemen’s safety gains might be the main incentives behind the implementation of the design in Cairo. Cairo motorists currently suffer excessive delays due to the poor performance of the unconventional MUT design. However, traffic officials in Egypt believe that this design is a ideal solution to enforce traffic laws.

01329018

11-3739

English

18p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (8) ; References (21)

Four leg intersections; Highway capacity; Highway design; Intersections; Measures of effectiveness; Medians; Microsimulation; Performance measurement; U turns

Median U-turn intersections

Cairo (Egypt)

Design; Highways; Operations and Traffic Management; I20: Design and Planning of Transport Infrastructure

Transportation Research Board Annual Meeting 2011 Paper #11-3739

TRIS, TRB

Feb 17 2011 6:37PM