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This study aimed to investigate red-light violations and their influencing factors at traffic signals in four major cities in Jordan. Field data was collected from 30 traffic signals in Amman, Zarqa, Jerash and Irbid cities. The intersection type, leg grade and speed of the subject's approach data was collected through field surveys and measurements, while the red-light violation data was collected from the recorded videos. The study analysis showed that among 3,444 drivers who had the chance to violate a red light, 436 (12.66%) drivers ran a red light. Pickup drivers had the highest violation rate among all drivers, with a rate of 21.4%, while heavy-vehicle drivers showed the lowest percentage of violation, at 11.18% for buses and 8.24% for trucks. The analysis showed that four-leg intersections had a higher violation rate than three-leg intersections. Also, drivers tended to show more violations on upgrade intersection approaches, with almost the same violation behavior on level and downgrade intersection approaches. According to traffic movement type, the analysis results showed that through-moving vehicles had the highest violation rate among all movement types, followed by left-turners, while the lowest violation rate was observed among U-turn movements. Referring to the location of the intersection, the violation rate was 13.48% in urban areas and 11.37% in sub-urban areas. The results showed that drivers tend to violate red lights more during fall than in spring. It was found that about 21% of drivers who arrived at the intersection at the beginning of red time violated the red light, while only 3.53% violated the red light during the rest of the red time interval. In addition, the percentage of red-light violations was directly proportional to the subject approach speed and total traffic volume entering the intersection and was inversely proportional to the conflicting traffic volumes. [ABSTRACT FROM AUTHOR]

Interchanges are constructed in urban and suburban areas to ease traffic operation. Outer connection ramps constitute a major part of interchanges planning and design. The objective of this study was to estimate interchange ramp capacity and investigate the impacts of ramp geometry on the obtained capacity. To achieve this objective, 20 ramps were selected, including 10 circular ramps and 10 curve-straight-curve ramps. Capacity of ramp proper and ramp exit were investigated in the study. At ramp proper, data on traffic speed and traffic flow were collected at 1 -minute intervals using video camera. Also, traffic data for ramp exit and mainline traffic were obtained under queued traffic condition on the ramp exit. An empirical approach using regression analysis was adopted to estimate capacity of the selected ramps and explore the impact of geometric design and traffic variables that might affect the estimated capacity. For ramp proper, the analyses revealed that the relationship between traffic speed and density is linear and between speed and traffic flow is parabolic irrespective of ramp configuration. For circular ramps, the capacity was found to vary from 1470 to about 2100 pc/hr./lane, and it was found that ramp radius is the most influencing factor in capacity estimation. For curve-straight-curve ramps, the results indicated that the obtained capacity varied from 1490 to 2200 pc/hr./lane, and both the straight segment length and the radius of the first curve are the most influencing factors. Also, it was found that ramp exit capacity is affected by flow and speed of traffic in the mainline street and degree of curvature of ramp exit curve. Finally, it was concluded that the use of curves with large radii at ramp proper and exit would increase ramp capacity, and customization of capacity values to reflect local conditions would provide more realistic estimates. [ABSTRACT FROM AUTHOR]

This paper includes a simulation-based analysis of non-stop traffic at isolated signalised intersections. A Min-Max traffic control method is proposed to replace conventional traffic signals and maintain a continuous traffic flow. The method applicability is tested by means of Discrete Event Simulation (DES) using AutoMod software package. A set of quantitative Measures of Performance (MOP) is used to demonstrate the benefits of the proposed method compared to conventional traffic signals. In addition to eliminating vehicles stoppages, simulation results of the proposed method showed improvement in the overall traffic flow by reducing vehicle average travel time, average delay time, and the average number of vehicles at the intersection. The proposed method can be adapted to suit other types of traffic intersections and flow patterns and conditions. [ABSTRACT FROM AUTHOR]

The purpose of this research was to develop a model for estimating roundabout delay as a function of the influencing traffic and geometric factors. Fourteen roundabouts were selected from different cities in Jordan. Circulating volume, entry volume, and entry delay were measured during peak and off-peak periods using video cameras. Data on geometric design elements including circulating width, entry width, and roundabout diameter were measured through field survey. An empirical approach was used to develop a delay model as a function of the influencing factors based on a time interval of 15 min. The analysis indicated that geometric variables have significant effects on the roundabout entry delay. The entry width has the greatest influence, whereas the circulating width has the least influence. A comparison between delay models produced using different time intervals showed that, as time interval increases, R[sup 2] increases. The SIDRA delay model was validated using the field delay data, and it was found that it overestimates the delay, especially at high delay ranges. The M/M/1 (random arrivals, random services, and a single service channel) queuing delay model was also validated using the field delay data, and it was found that it estimates delay with high variability, especially for high delay ranges. [ABSTRACT FROM AUTHOR]