Item B: West 11th Transportation Corridor Study

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Reducing the number of driveway accesses in the corridor presents the best opportunity to improve safety for motorists, bicyclists and pedestrians. Management of the driveway accesses through closing, combining or modifying driveways must be consistent with adopted access management policies and code authority delegated to the City Traffic Engineer for safe operation of the transportation system. The access management policies are focused on addressing access conflicts over time through redevelopment of property. It may take considerable time to reduce the access conflicts in the corridor with this approach, depending on the pace of redevelopment. Another option is for the City to initiate safety improvement projects that could sensitively close, combine or modify accesses in a way that works for th property owners and businesses along West 11 Avenue. Signal Timing th Most of the traffic signals in the corridor are operating very well. The West 11 Avenue corridor is under Oregon Department of Transportation (ODOT) jurisdiction west of Randy Papé Beltline and City jurisdiction to the east of Randy Papé Beltline. All of the traffic signals under City jurisdiction currently meet the adopted mobility standard. Traffic signals under ODOT jurisdiction, however, did fail to meet ODOT mobility standards (currently) and would be expected to worsen in the short-term (2013) without improvements. The City measures mobility as Level of Service (LOS) on a letter grade scale from A through F (similar to a report card) based on delay criteria. The City-adopted mobility standard is Level of Service D outside of the downtown core and university area (within the Central Area Transportation Study boundary the mobility standard is Level of Service E, allowing for more congestion). Higher levels of service (A through C) experience less congestion and relatively little delay. Level of Service D and below (E-F) represents congested conditions, increasing delay and interrupted operations in the worst cases. Level of Service E and F are the types of congestion that most people easily recognize through their driving as it takes multiple cycles to make it through a traffic signal. th For the West 11 Avenue Corridor Study, signalized and non-signalized intersections were evaluated for both delay (to determine operational LOS) and demand-to-capacity ratios (required for ODOT thth facilities). At the east end, additional traffic signals were evaluated on 6 and 7 avenues at Garfield and thth Chambers streets (ODOT), and 11 and 13 avenues at Garfield and Chambers streets (City). The study evaluated opportunities to improve traffic flow (reduced stopped delay) by looking at different traffic signal cycle lengths and phase sequencing for both morning and evening peaks. The th signal timing analysis for the West 11 Avenue corridor indentified opportunities for moderate time savings, reduced congestion and delay. Based on retiming traffic signals and changing the way left- turning phases are operated, it is expected that a reduction of 4-14% of the stopped delay could be achieved. This represents a marginal improvement in operations that may be difficult for most motorists to perceive for through-trips and would likely offer noticeable benefit to left-turning motorists at signalized intersections. Traffic signal retiming and changes to phasing for some left turns can result in real reductions in vehicle emissions and fuel consumed when aggregated over the many motor vehicles using the corridor daily and annually. Individual drivers may not perceive much change, but when added up over all those vehicles traveling the corridor, the reductions become significant. Cost to retime the traffic signals could Z:\CMO\2010 Council Agendas\M100712\S100612B.doc