INTERSECTION CONTROL EVALUATION
> PURPOSE
Intersection Control Evaluation (ICE) is a directive issued by the California Department of Transportation (Caltrans) for all proposed highway intersection projects, whether new or for improvement. ICE is performed during the early stages of a project, allocating time to study which types of intersection control alternatives would work. Control types listed by ICE include stop, signal, roundabout and lane configuration changes. Each is to get ample time for consideration.
> NEED FOR CONTROL
The project site is located in a heavily traveled corridor within the City of Moreno Valley. The interchange serves as an arterial between future residential expansion and future commercial properties. There will be significant truck and passenger vehicle volume increases for this interchange. Therefore, it is necessary to assess the feasibility of various control types for this project.
The four study intersections include
The images below describe the existing configurations of the 4 study intersections.
The four study intersections include
- Theodore Street and Eucalyptus
- Theodore Street and SR-60 Eastbound ramps
- Theodore Street and SR-60 Westbound ramps
- Theodore Street and Ironwood Avenue
The images below describe the existing configurations of the 4 study intersections.
> CONTROL TYPES
Stop Control
A stop controlled intersection involves placing stop signs at the intersection, making vehicles that pass through it have to stop and pass with caution. The existing configuration of the interchange is stop controlled. A synchro analysis of the future volumes using this configuration was done to evaluate if keeping stop signs a viable control for each intersection.
Yield (Roundabout) Control
Yield control involves slowing vehicle speed to a safe level while making them pay attention to other vehicles in the intersection. One type of yield control is the roundabout, a typically circular road where vehicles can enter and exit from different directions. There is enough right of way to design a traditional roundabout, possibly with an increase of interior lanes and a road diet of the surrounding area. A synchro analysis of the future volumes using a roundabout configuration was done to evaluate if a yield control would be an acceptable intersection control.
Signalized Control
A signalized control uses traffic lights to coordinate movements in an intersection. This should be the last control type to be considered. If a stop or yield control cannot hold the capacity of vehicles, a traffic signal would be the optimal traffic control for the intersection. A synchro analysis of the future volumes using a signalized control at each intersection was done to evaluate the optimal signalized configuration.
Each of these three controls were evaluated for each intersection for all 5 alternatives. We looked at the Level of Service for the three control types. If a stop controlled intersection yielded a Level of Service of a D or better, we would use that intersection control. If the stop control had a failing Level of Service, we tested the intersection with a roundabout or yield control. If the roundabout yielded a Level of Service of a D or better, we would use that intersection control. If both a roundabout and stop sign failed to meet the Level of Service necessary, a signalized intersection control was analyzed to meet the Level of Service of a D or better.
A stop controlled intersection involves placing stop signs at the intersection, making vehicles that pass through it have to stop and pass with caution. The existing configuration of the interchange is stop controlled. A synchro analysis of the future volumes using this configuration was done to evaluate if keeping stop signs a viable control for each intersection.
Yield (Roundabout) Control
Yield control involves slowing vehicle speed to a safe level while making them pay attention to other vehicles in the intersection. One type of yield control is the roundabout, a typically circular road where vehicles can enter and exit from different directions. There is enough right of way to design a traditional roundabout, possibly with an increase of interior lanes and a road diet of the surrounding area. A synchro analysis of the future volumes using a roundabout configuration was done to evaluate if a yield control would be an acceptable intersection control.
Signalized Control
A signalized control uses traffic lights to coordinate movements in an intersection. This should be the last control type to be considered. If a stop or yield control cannot hold the capacity of vehicles, a traffic signal would be the optimal traffic control for the intersection. A synchro analysis of the future volumes using a signalized control at each intersection was done to evaluate the optimal signalized configuration.
Each of these three controls were evaluated for each intersection for all 5 alternatives. We looked at the Level of Service for the three control types. If a stop controlled intersection yielded a Level of Service of a D or better, we would use that intersection control. If the stop control had a failing Level of Service, we tested the intersection with a roundabout or yield control. If the roundabout yielded a Level of Service of a D or better, we would use that intersection control. If both a roundabout and stop sign failed to meet the Level of Service necessary, a signalized intersection control was analyzed to meet the Level of Service of a D or better.
> ALTERNATIVE INTERSECTION CONTROL EVALUATIONS
Hybrid Diamond Evaluation Summary
Stop control, roundabout control and non-traditional control at intersections 1, 2 and 3 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for intersections 1, 2, and 3 are the likely candidates to be chosen for the HDI and therefore recommended for the project. Intersection 4’s LOS does not change with the existing lane configuration and control type. Therefore, intersection 4 will stay stop controlled.
Stop control, roundabout control and non-traditional control at intersections 1, 2 and 3 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for intersections 1, 2, and 3 are the likely candidates to be chosen for the HDI and therefore recommended for the project. Intersection 4’s LOS does not change with the existing lane configuration and control type. Therefore, intersection 4 will stay stop controlled.
Partial Cloverleaf Evaluation Summary
Stop control, roundabout control and non-traditional control at intersections 1, 2 and 3 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for intersections 1, 2, and 3 are the likely candidates to be chosen for the ParClo and therefore recommended for the project. Intersection 4’s LOS does not change with the existing lane configuration and control type. Therefore, intersection 4 will stay stop controlled.
Stop control, roundabout control and non-traditional control at intersections 1, 2 and 3 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for intersections 1, 2, and 3 are the likely candidates to be chosen for the ParClo and therefore recommended for the project. Intersection 4’s LOS does not change with the existing lane configuration and control type. Therefore, intersection 4 will stay stop controlled.
Diverging Diamond Evaluation Summary
Based on the Synchro analysis the Roundabout and stop control are not suitable for intersection 1. For intersection 4 the current stop control still receives an A grade and does not need to be changed to a roundabout or signal control. Intersections 2 and 3 use the DDI as a special intersection control. The crossover movements only require a two-phase signal. This reduces delay time. In table 5 below the recommendations for the intersection control are shown with their respective LOS grade.
Based on the Synchro analysis the Roundabout and stop control are not suitable for intersection 1. For intersection 4 the current stop control still receives an A grade and does not need to be changed to a roundabout or signal control. Intersections 2 and 3 use the DDI as a special intersection control. The crossover movements only require a two-phase signal. This reduces delay time. In table 5 below the recommendations for the intersection control are shown with their respective LOS grade.
Single Point Urban Interchange Evaluation Summary
Stop control, roundabout control, and non-traditional control at intersections 1 and 2 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected for these two intersections. Since the level of service for Intersection 3 will continue as a stop control with the same lane configurations.
Based on an evaluation using predicted traffic conditions, signalized control for all intersections is the likely candidate to be chosen for the SPUI and therefore recommended for the project.
Stop control, roundabout control, and non-traditional control at intersections 1 and 2 are not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected for these two intersections. Since the level of service for Intersection 3 will continue as a stop control with the same lane configurations.
Based on an evaluation using predicted traffic conditions, signalized control for all intersections is the likely candidate to be chosen for the SPUI and therefore recommended for the project.
Continuous Flow Evaluation Summary
Stop control, roundabout control and non-traditional control at intersections is not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for all intersections is the likely candidate to be chosen for the CFI and therefore recommended for the project.
Stop control, roundabout control and non-traditional control at intersections is not likely to work due to high volumes that are projected to exist within the life of the proposed project, year 2040. Therefore, these alternatives will be rejected.
Based on an evaluation using predicted traffic conditions, signalized control for all intersections is the likely candidate to be chosen for the CFI and therefore recommended for the project.
> ATTACHMENTS
Provided below is a link to the SR-60 and Theodore Intersection Control Evaluation Report.
SR-60 & Theodore ICE | |
File Size: | 2203 kb |
File Type: |