Challenge

N Sycamore Street is a key connection on the west side of Arlington County, VA to I-66 and Lee Highway. To better connect the surrounding neighborhoods to the East Falls Church transit center—which connects Metrorail Metrobus, Arlington Regional Transit, and the Fairfax Connector—the County proposed improvements near the I-66 off-ramp intersection. Because these modifications could impact queuing along the ramp to the I-66 through lanes, an Operational and Safety Analysis Report (OSAR) was required for VDOT review and approval.

Solution

Kittelson collaborated with the County and VDOT to develop framework documentation to scope the extents, methods, and goals of the study and help determine the best solution from a traffic operations perspective. The analysis included volume forecasting, planning-level traffic analysis techniques to evaluate lane configuration options, and SimTraffic microsimulation to analyze queuing impacts. Flexing traffic signal timing, phasing, and coordination, the analysis showed improvements to the intersection could still mitigate queuing within the off-ramp storage.