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ST0501-CS080829 MEMORANDUM FROM THE DEPARTMENT OF ENGINEERING To: Ken Griffin, P.E., Director of Engineering and Public Works From: DiWanna Baskins, Graduate Engineer Date: August 29, 2008 RE: Request for Traffic Signal at the Intersection of Deforest Rd. and MacArthur Blvd. This traffic study is in response to requests from citizens in subdivisions adjacent to Deforest Rd., inquiring if a signal could be installed to enhance the intersection due to the widening of Deforest Rd. The Texas Manual on Uniform Traffic Control Devices is used to decipher if the intersection warrants a traffic signal based off the traffic study conducted on March 27, 2008. Refer to Section 4C.01, Studies and Factors for Justifying Control Signals for this study. Warrant 1, Eight –Hour Vehicular Volume Standard: The need for a traffic control signal shall be considered if an engineering study finds that one of the following conditions exist for each 8 hours of an average day: A.The vehicles per hour given in both of the 100 percent columns of Condition A in Table 4C-1 exist on the major-street and the higher- volume minor- street approaches, respectively, to the intersection; This intersection does not meet this requirement. OR B.The vehicles per hour given in both of the 100 percent columns of Condition B in Table 4C-1 existing on the major-street and the higher- volume minor-street approaches respectively, to the intersection. This intersection meets this requirement. Standard: The need for a traffic control signal shall be considered if an engineering study finds that both of the following conditions exist for each 8 hours of an average day: A.The vehicles per hour given in both of the 80 percent columns of Condition A in Table 4C-1 exist on the major-street and the higher-volume minor-street approaches, respectively, to the intersection; This intersection does not meet this requirement. "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN" AND B.The vehicles per hour given in both of the 80 percent columns of Condition B in Table 4c-1 exist on the major-street and higher-volume minor-street approaches, respectively, to the intersection. This intersection does not meet this requirement. Warrant 2, Four –Hour Vehicular Volume Standard: The need for a traffic control signal shall be considered if an engineering study finds that, for each of any 4 hours of an average day, the plotted points representing the vehicles per hour on the major street (total of both approaches) and the corresponding vehicles per hour on the higher-volume minor-street approach (one direction only) all fall above the applicable curve in Figure 4C-1 for the existing combination of approach lanes. On the minor-street, the higher volume shall not be required to be on the same approach during each of these 4 hours. This intersection meets this requirement. Warrant 3, Peak Hour Standard: This signal warrant shall be applied only in unusual cases. Such cases include, but are not limited to, office complexes, manufacturing plants, industrial complexes, or high-occupancy vehicle facilities that attract or discharge large numbers of vehicles over a short time. This intersection does not meet this requirement. The need for a traffic control signal shall be considered if an engineering study finds that the criteria in either of the following two categories are met: A.If all three of the following conditions exist for the same 1 hour (any four consecutive 15 minute periods) of an average day: 1.The total stopped time delay experience by the traffic on one minor-street approach (one direction only) controlled by a STOP sign equals or exceeds: 4 vehicle-hours for a one-lane approach; or 5 vehicles-hours for a two lane approach, AND 2.The volume on the same minor-street approach (one direction only) equals or exceeds 100 vehicles per hour for one moving lane of traffic or 150 vehicles per hour for two moving lanes, AND 3.The total entering volume serviced during the hour equals or exceeds 650 vehicles per hour for intersections with three approaches or 800 vehicles per hour for intersection with four or more approaches. B.The plotted point representing the vehicles per hour on the major street(total of both approaches) and the corresponding vehicles per hour on the higher-volume minor-street approach (one direction only) for 1 hour (any four consecutive 15 minute periods) of any average day falls above the applicable curve in Figure 4C-3 for the existing combination of approach lanes. "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN" Warrant 4, Pedestrian Volume Standard: The need for a traffic control signal at an intersection or midblock crossing shall be considered if an engineering study finds that both of the following criteria are met: A.The pedestrian volume crossing the major street at an intersection or midblock location during and average day is 100 or more for each of any 4 hours or 190 or more during any 1 hour; This intersection does not meet this requirement. AND B.There are fewer than 60 gaps per hour in the traffic stream of adequate length to allow pedestrians to cross during the same period when the pedestrian volume criterion is satisfied. Where there is an divided street having a median of sufficient width for pedestrians to wait, the requirement applies separately to each direction of vehicular traffic. This intersection does not meet this requirement. Warrant 5, School Crossing Standard: The need for a traffic control signal shall be considered when an engineering study of the frequency and adequacy of gaps in the vehicular traffic stream as related to the number and size of groups of school children at an established school crossing across the major street shows that the number of adequate gaps in the traffic stream during the period (see Section 7A.03) and there are a minimum of 20 students during the highest crossing hour. Before a decision is made to install a traffic control signal, consideration shall be given to the implementation of other remedial measures, such as warning signs and flashers, school speed zones, school crossing guards, or a grade-separated crossing. The School Crossing signal warrant shall not be applied at locations where the distance to the nearest traffic control signal along the major street is less than 300 ft., unless the proposed traffic control signal will not restrict the progressive movement of traffic. This intersection does not meet this requirement. Warrant 6, Coordinated Signal System Standard: The need for a traffic control signal shall be considered if an engineering study finds that one of the following criteria is met: A.On a one-way street or a street that has traffic predominantly in one direction; the adjacent traffic control signals are so far apart that they do not provide the necessary degree of vehicular platooning. This intersection does not meet this requirement. "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN" B.On a two-way street, adjacent traffic control signal do not provide the necessary degree of platooning and proposed and adjacent traffic control signal will collectively provide a progressive operation. This intersection does not meet this requirement. Warrant 7, Crash Experience Standard: the need for a traffic control signal shall be considered if an engineering study finds that all of the following criteria are met: A.Adequate trial of alternatives with satisfactory observance and enforcement has failed to reduce the crash frequency; and This intersection does not meet this requirement. AND B.Five or more reported crashes, of types susceptible to correction by a traffic control signal, have occurred within a 12- month period, each crash involving personal injury or property damage apparently exceeding the applicable requirement for a reportable crash; and This intersection does not meet this requirement. AND C.For each of any 8 hours of an average day, the vehicles per hour (vph) given in both of the 80 percent columns of Condition A in table 4C-1 (see Section 4C.02), or the vph in both of the 80 percent columns of Condition B in Table 4C-1 exists on the major-street and the higher- volume minor-street approach, respectively, to the intersection, or the volume of pedestrian traffic is not less than 80 percent of the requirements specified in the Pedestrian Volume warrant. These major-street and minor-street volumes shall be for the same 8 hours. On the minor street, the higher volumes shall not be required to be on the same approach during each of the 8 hours. This intersection does not meet this requirement. Warrant 8, Roadway Network Standard: The need for a traffic control signal shall be considered if an engineering study finds that the common intersection of two or more major routes meets one or both of the following criteria: A.The intersection has a total existing, or immediately projected, entering volume of at least 1,000 vehicles per hour during the peak hour of a typical weekday and has 5- year projected traffic volumes, based on an engineering study, that meet one or more of Warrants 1, 2, and 3 during an average weekday; or This intersection does not meet this requirement. OR B. The intersection has a total existing or immediately projected entering volume of at least 1,000 vehicles per hour for each of any 5 hours of a non-normal business day (Saturday or Sunday). This intersection does not meet this requirement. A major route as used in this signal warrant shall have one or more of the following characteristics: "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN" A.It is part of the street or highway system that serves as the principal roadway network for through traffic flow; This intersection does meet this requirement. OR B.It includes rural or suburban highways outside, entering, or traversing a City; or This intersection does not meet this requirement. OR C.It appears as a major route on an official plan, such as a major street plan in an urban area traffic and transportation study. This intersection does meet this requirement. Recommendation/Comments According to Section 4C.01 of the TMUTCD manual, the intersection of Deforest Road and MacArthur Blvd satisfies two of the warrants for justifying control signals. The intersection of Deforest Road and MacArthur is unique because it is located approximately 750 ft. north of the signalized intersection of Samuel Blvd. and MacArthur Blvd. Although, the intersection at Samuel Blvd. can be timed to coordinate with the Deforest Rd. and MacArthur intersection, it is not recommended to space signalized intersections less than 1000 ft. Taking into consideration the directional flow of traffic during peak hours, recommended cycle length time, and the fact that approximately 37 vehicles can be stacked in-between the signalized intersections may not create ideal conditions during peak hours because turns onto MacArthur may create a “bottleneck” effect. However, the nearest signalized intersection south of Samuel Blvd. and MacArthur Blvd. is Parkway Blvd and MacArthur Blvd. Appropriate signal timing may eliminate a bottleneck effect if vehicles proceeding onto MacArthur during peak hours are allowed through the intersection of Samuel and MacArthur by coordinating both signals, provided that stacking does not exceed occupancy in-between the next signalized intersection. In the event that a traffic signal is installed, the intersection of Deforest Road and MacArthur should be closely monitored so that the timing of the traffic signals will allow vehicles to progress smoothly. "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"