Effect of On-Street Parking and Pedestrian Crossing on Through Traffic in Jordan
Authors: Khasawneh Mohammad Ali , Al-Omari Aslam Ali , Al-Jarazi Rabea 
Published: January 2023

Background:
With the dramatic rapid increase in population growth and in the use of the automobile in the world, especially in developing countries such as Jordan, related traffic problems have become more and more complex. Parking is one of the major problems that are created by increasing road traffic. Both on-street parking and pedestrian crossing are important components of the urban transport system. On-street parking is an important component of the parking system. Because of its occupancy of roadway resources, it can significantly impact traffic performance and safety. The lack of providing an adequate number of parking areas within urban central business districts (CBDs) and the lack of off-street facilities in urban neighborhood commercial areas, both result in increased on-street parking and disturbance of traffic stream. The management of on-street parking is one of the main parameters in traffic management.
In developing countries, as the number of vehicles and parking demand had increased significantly in recent years, on-street parking-related concerns are no longer confined to the city center; they extend throughout the whole urban region. Furthermore, the correlation between on-street parking and traffic safety is still a controversial issue. The research findings of this study help to develop a better understanding of both on-street parking and pedestrian crossing at mid-block location and help to plan and design proper transportation facilities on urban streets.
The model of this study can give quantitative results regarding the influence of on-street parking on through traffic operations. Findings of the study can support municipal engineering (policy decisions) for on-street parking hour permits. As delay on the street segment and road network can be calculated, municipal engineering (policy makers) can set up a maximum tolerable threshold in the delay profile to decide when street parking is permitted on which network path for how many vehicles. A time varying parking fee policy can be proposed according to actual delay caused by the parked vehicles at the entire network or the like. Many engineers are concerned about the increase in the number of accidents which are associated with on-street parking. In addition to the above-mentioned issues concerning the relationship of on street parking with through traffic movements, the pedestrian is one of the important components in urban transportation system and is vulnerable at unprotected mid-block locations under high traffic conditions.
At unprotected mid-block locations, some vehicles may yield to pedestrians who are already at crosswalk location. Moreover, because of poor construction of separated facilities and road side development especially in developing countries, pedestrians usually cross the road at unprotected mid-block locations under high traffic conditions. Furthermore, the use of most major streets in developing countries such as Jordan are not properly monitored and managed especially with regards to on-street parking and pedestrian crossing, and therefore reducing the capacity of roadways and probably causing accidents. This research could provide insights for transportation agencies as it is related to traffic operations issues and safety especially in developing countries.

Objective:
1. Investigate the effect of on-street parking on through traffic in terms of delay.
2. Develop a model that can estimate the effect of on-street parking on through traffic.
3. Investigate the effect of pedestrian crossing on travel time.

Method:
Data was collected using a video camera for a total of 37 street segments from three major cities in Jordan, during off-peak hour and dummy regression was used for analysis.

Result and Discussion:
Results revealed that on-street parking maneuvers (in/out) and pedestrian forced gap can significantly influence through traffic characteristics of Jordan traffic network. The trend of traffic volume was found to fall gradually, while average delay time was found to rise gradually with an increase in the number of parking maneuvers (in/out). The average percent reduction in maximum traffic volume at one lane was 28.7% which was more than that at two lanes (18.6%) under high parking maneuver conditions. The average delay time caused by heavy vehicles, angle parking, street without median, and street in a central business district (CBD) commercial area was more than that caused by the presence of passenger vehicles, parallel parking, street with median, and street in non-CBD commercial area by 27.8%, 31.7%, 29.7%, and 10.0%, respectively. The vehicular speeds had a significant drop reaching a value of 32.0% on average with pedestrian crossing when compared to no pedestrian crossing at mid-block location. A prediction model using dummy regression was proposed and shown to be able to predict average delay time.

Conclusion:
1. On-street parking maneuvers can significantly influence the maximum traffic volume of street segments in Jordan.
2. A trend for traffic volume to fall gradually with an increase in the number of parking maneuver (in/out) was concluded.
3. The average percent reduction in maximum traffic volume at one lane (28.7%) was more than that at two lanes (18.6%) where there is high parking maneuver. Of all the factors that can impede the flow of traffic on the roadway, on-street parking can be considered the most important factor. The reduction of roadway width by the owners of shops who sometimes occupy one lane of the roads also affects the traffic operation and reduces traffic volume.
4. A trend for average delay time to rise gradually with an increase in the number of parking maneuver (in/out) was concluded.
5. The average delay time caused by heavy vehicles, angle parking, street without median and street in CBD commercial areas was more than that caused by the presence of passenger vehicles, parallel parking, street with median and street in non-CBD commercial by 27.8%, 31.7%, 29.7%, and 10.0%, respectively. Also, on-street parking maneuvers may be a contributory factor to causing temporary bottlenecks in moving traffic, which may result in causing more operational problems such as congestion and accidents.
6. The vehicular speeds were implicitly affected by pedestrian crossing when compared to no pedestrian crossing location. In other words, there was a significant drop of speed value reaching an average of 32.0%.
7. Compared with the effects of all the independent variables, number of parking maneuvers has the greatest influence on the estimated average delay time.
8. Prediction models using dummy regression were proposed and shown to be able to predict average delay time if provided inputs are within the data range used in developing the models.