Transportation System Plan 2018-2038

The program SIMTRAFFIC was also used to analy ze traffic operations throughout the City of Medford. SIMTRAFFIC uses the SYNCHRO m odel as input and provides a graphical representation of the traffic system operation. The graphical display shows all roadway s contained in the SYNCHRO m odel (including the roadway geom etric features) and indi vidual vehicles traveling through the network. The SIMTRAFFIC sim ulation was used to determ ine lo cations where the HCM report m ight indicate an acceptable level of service for an intersection as a whole but som e particular m ovem ents m ight not be serviced adequately thus causing queues to spill back from the intersection, effecting the operation at adjacent intersections. The City of Medford provided a base-y ear SYNCHR O model and 2002 traffic counts for all signalized intersections throughout the City . The base-y ear SYNCHRO m odel was reviewed for consistency with existing signal tim ing, roadway geom etry and other input factors. The SYNCHRO model contains a series of nodes and links that represent intersections and roadway s throughout the City of Medford. The base m odel received from the city was revised to m ore closely represent actual roadway alignm ents and intersection geom etric features. In addition, arteria l/arterial, collector/collector, and arterial/collector intersections that were not included in the base model were added. The review was based on inform ation contained in an AutoCAD file provided by the C ity showing roadway striping, on aerial photographs provided by the City , traffic studies perform ed in the areas, and through field visits. The City of Medford also provided existing signal tim ing data sheets for all signalized intersections within the City . The signal timing data contained in the base SYNCHRO m odel we re reviewed and m odified as needed to rem ain consistent with actual tim ing in the field. While reviewing the base m odel from the city , it was learned that m ore recent traffic counts were available (from 2002). The 2000 counts contained in the base m odel from the City were replaced with the more current 2002 counts. The traffic counts at each intersection were reviewed and m odified as needed to maintain a reasonable balance between infl ow and outflow volum es on each roadway segm ent throughout the network. Traffic count data was av ailable for all signalized intersections analy zed; however, count data was not available for all unsignali zed intersections included in the analy sis. A listing of intersections with m issing count data is provi ded in Appendix A of the LOS Study Final Report. Traffic volum es within the vicinity of the Highway 238 Project area should be r ecounted and re-evaluated since the 2002 counts were taken shortly after ope ning of the new Highway 238 by pass and m ay have been influenced by traffic volum e shifts associated with the Medford Viaduct Project. In som e cases the counted volum es were significantly different than th e predicted volum es contained in the Environm ental Assessm ent for the Highway 238 Project. It is anticip ated that m any motorists m ay not have becom e completely familiarized with the new roadway connec tions by the tim e the traffic counts were taken. The base-y ear model includes all signalized intersections as well as all arterial/ arterial, arterial/ collector, and collector/ collector intersections regardless of the type of intersection control provided (i.e., unsignalized intersections m eeting these criteria were also included in the m odel). The base-y ear m odel was then used to predict the level of operation of each intersection throughout the city given 2023 traffic volum es. The base-y ear m odel was revised to in clude com mitted roadway projects and to reflect 2023 traffic volum es, as described later in this section. Level of Service (LOS) and Volume-to -Capacity (V/C) Ratio Mobility Measures LOS quantifies the degree of comfort (including such elem ents as travel tim e, num ber of stops, total amount of stopped delay and impedim ents caused by other vehicles) afforded to drivers as they travel through an intersection or along a roadway section. It was developed to quantify the quality of service of transportation facilities. In general, level of service is based on total delay . This param eter is defined as the total elapsed tim e from when a vehicle stops at the end of a queue until the vehicle departs from the G-3