Orange County NC Website
Browse       Search
August 5, 2020 <br />Mr. Chuck Edwards, PE, District Engineer <br />Page 2 of 15 <br />Reference: Research Triangle Logistics Park TIA Supplement <br /> <br /> <br /> <br />Old NC 86 interchange. The I-3306 Traffic Capacity Analysis prepared by Kimley-Horn and Associates <br />recommends that signals be installed at both ramps with an additional southbound left turn lane and an <br />exclusive northbound right turn lane at the eastbound ramp. The improvements are illustrated in the <br />attached Figure 7A. The I-3306A Public Meeting Map (Sheet 2 of 6) from the January 24, 2019 illustrates <br />improvements at the intersection, but they are not consistent with the recommendations in the Capacity <br />Report. According to this figure, traffic signals are not being shown at the ramps. A southbound right turn <br />at the I-40 westbound on-ramp is shown on the plan as well as a northbound right turn lane and an <br />additional receiving lane on the I-40 eastbound ramp. Although there will be two receiving lanes on the <br />ramp, the plan does not show dual southbound left turns even though the volume of traffic making this <br />movement is extremely high. The interchange portion of the Public Hearing Map is attached to this <br />supplement. <br />Analysis Results and Mitigation Requirements: <br />Old NC 86 and Waterstone Drive / Rippy Lane Intersection: <br />All parties are all in agreement that no improvements are required. <br />Old NC 86 & I-40 Westbound Ramps <br />According to the TIA that was completed for Settler’s Point, signal warrant analyses were conducted for this <br />intersection and it was noted that warrants were met for signalization in the no build condition. Due to the <br />data collection restrictions caused by the Covid Pandemic, the same data were used for the Research <br />Triangle Logistics Park, so the same results would apply to this study. The section of Settler’s Pointe <br />discussing signal warrants is attached. <br />As noted in the TIA, we recognize that there is an increase in delay for the westbound approach at the Old <br />NC 86 intersection with the I-40 WB ramp. It is not unusual for a minor approach at an unsignalized <br />intersection to have an unacceptable level of service. According to the NCDOT Congestion Management <br />Capacity Analysis Guidelines, “a poor level of service on a side street does not always result in a <br />recommendation for signalization if v/c ratios and queuing are acceptable”. The v/c ratio for the westbound <br />left turn is 0.59 and 0.65 in the AM and PM peak hours, respectively. Based on SimTraffic models, <br />although there will be delay on the ramp, there is sufficient storage to ensure that traffic accessing Old NC <br />86 will be stored on the ramp with no impacts on I-40. Additionally, it should be noted that the TIA assumed <br />full build out of Waterstone while the development is only partially built out. Therefore, delay estimates are <br />very conservative. The U-5845 project will install a signal at this location. <br />Therefore, based on this additional information, we do not recommend improvements at this location as a <br />result of the proposed development. <br /> <br />47