Baltimore-Washington Parkway Widening Feasibility Study

Baltimore-Washington Parkway Widening Feasibility StudyTraffic and Transportation Impacts5.4.2OperationsResults from the Highway Capacity Software (HCS) analysis were used to develop comparisons betweenthe various scenarios to ascertain the impact of widening on individual users. With the intention oflimiting this comparison to “significant” differences between the defined analysis scenarios, ignoringminor variations of operational characteristics that occur with small changes in traffic volumes, thesecomparisons focused on a segment-by-segment review of where the level-of-service letter-grade asreported by HCS changed between scenarios.5.4.2.1ExistingConditionsThe results of this analysis show peak hour mainline segments generally operating at conditionsbetween level-of-service “C” and “F” throughout the corridor. Traffic operations in the range of level-ofservice“C” or “D” typically consist of travel at or near the free flow speed, with drivers increasinglyconstrained by surrounding vehicles. Level-of-service “E” or “F” conditions are indicative of operationsat or near capacity and where congestion-related delays begin to have significant impacts on road usersin the form of significantly reduced travel speeds; from 5 miles per hour or more below free-flow speedsdown to stop-and-go traffic conditions. Several “hot spot” segments were identified where mainlinesegments were experiencing level-of-service “E” or “F” and are highlighted in Figure 5.6.Figure 5.6. Parkway Segments Currently Operating at or Near Capacity(Level-of-Service “E” or “F”)49 November 2012