Hank Warner of DMJM + Harris presented information on the traffic studies. Hank stated that a traffic report was completed several years ago to predict what traffic will be like on Craycroft in the future. Hank explained that two methods were employed to estimate future traffic counts. The first one used the Pima Association of Governments' (PAG) computer model. This computer model was utilized to produce a report with a 20 to 25 year traffic projection. The Craycroft Team then generated another traffic estimate, which used the general assumption of a 3% yearly growth rate. This projection came back higher than the PAG estimate; therefore, it will be used for design since it is the more conservative forecast. Hank moved on to discuss the River Road/Craycroft intersection. Hank explained that a computer model was used to generate the level of service, A through F, depending on the counts taken. River Road/Craycroft was rated as the worst level of service, an F. He noted Sunrise also has a poor level of service. This project, in combination with the Sunrise Drive project (currently being completed), will improve the level of service at these intersections. Julia Gordon asked if the team is able to determine how long peak periods last. Hank answered that normally it takes place during the regular a.m. and p.m. rush hours; however, other periods of the day may also experience undesirable levels of service. Jeff Weatherford, Pima County Traffic Engineering, added that counts were also taken during the heavy peaks. These usually occur in the morning from 7:30 a.m. to 9:30-10:00 a.m. and in the afternoon from 2:00 p.m. to about 7:00 p.m. Once an intersection reaches the point of level of service F, the only way to fix it is to add lanes. The level of service is based on the amount of delay that is spent at each intersection. For an urban intersection, level of service D is considered an acceptable rate. This is a delay of 30 to 60 seconds. After the project is completed the level of service should improve to C. In the year 2020, according to Hank's numbers, the intersection should be barely getting to level of service E. It was noted that these peak values are also estimated to be somewhat conservative. Charles Geoffrion asked if these numbers take into account the shift (increase) in traffic once the Sunrise improvements are complete. Jeff answered that this construction has definitely increased the traffic on River. If the numbers were looked at before construction, the intersection was probably operating at a halfway decent rate. Once an intersection (two-lane) is handling 14,000 to 15,000 vehicles per day, plans need to be made to widen it to a four-lane roadway. Before Sunrise construction, Craycroft was already handling 16,000 to 17,000 vehicles per day, so it is time for this roadway to be expanded. The 2020 numbers projected north of River are about 30,000. This would not be considered enough to warrant a six-lane roadway, which requires approximately 40,000 vehicles. The four-lane roadway currently planned will provide good levels of service past the year 2020. Mr. Geoffrion asked if the traffic lights are adjusted according to demand. Jeff responded that the lights are working according to the demand during certain times of day. For example, in the morning the light will provide more green time than around noontime. Sal added that the 2020 projections in either case show that the widening is needed. The higher numbers are being used to plan the required storage lengths for left and right turns. The higher numbers will also be utilized to do the noise analysis. This will cause the noise analysis to predict higher noise levels, which will favor any needs for warranted noise mitigation measures. Donald Baker asked if the left turn at the intersection of River and Craycroft was to be taken out.
Sal explained that the left turn into the shopping center will remain but the left turn out of the shopping center will no longer be permitted. Mr. Baker noted that he uses the Sunrise and Swan intersection often. On that project, a left turn opening was removed and now traffic trying to go southbound has to make a u-turn at the intersection. The flow on Sunrise is being stopped by all the u-turn traffic. This scenario with all the congestion being created might repeat itself if this intersection is not looked at very closely. Jeff responded that the problem at Sunrise is that the heaviest traffic is in the morning going east to south (a right turn) and in the evening going north to west (a left turn). The reason it was designed this way is to provide sufficient storage for the northbound left turns. Mr. Baker added that since the numbers being used are numbers that are to occur 20 years from now, why not leave the median open for now and close it up later when higher traffic levels are reached or come up with an alternative. To wait 20 years for something to happen is causing problems (currently) by slowing everybody down. Mr. Baker noted another instance on River Road and Campbell Avenue where three westbound entrances were all closed up and people can no longer make a safe left turn into the shopping center. Hank acknowledged there are advantages and disadvantages in that case. The disadvantage is that if there was a full median opening, the queue from traffic exiting the parking lot would back up into the parking lot and the wait would be very long. There would also be the potential for traffic accidents to shut down the median opening. He pointed out on the map that if a vehicle makes a right turn out of the parking lot and then a u-turn at the next median opening, that this would be a fairly easy and safe maneuver. Mr. Baker pointed out that the level of accessibility that is provided to them affects the businesses and neighbors have to travel an extra mile or so to go someplace else. Hank responded that from a convenience stand point the median opening in the design plans for Craycroft Road will work better, as people will not have to drive far to make a u-turn. Julia Gordon asked how a vehicle making a u-turn would impact or slow down traffic since its being done on the lagging left signal. Mr. Baker responded that once that vehicle makes the turns it has to be sure to yield to oncoming traffic and to right turn traffic as well. Sal noted that this project appears to have a better design than others in the area and the county has done its best to learn from past experiences. Hank briefly reviewed the model numbers on display. He explained these are taken in a span of 24 hours in both directions, north and southbound.
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Year
2000 Seasonally Adjusted, 24 Hour, Two-Way Volumes
> Year
2020 - 24 Hour, Two-Way Volumes of Average Weekday
Traffic |
