Following the publication and review of the 6th Edition of the Highway Capacity Manual by the Transportation Research Board (TRB), McTrans has released the version of the Highway Capacity Software (HCS7) that implements the updated and new procedures. The new main menu simplifies options, but expands choices, with fewer buttons for a more consolidated view with each including specific modules for analysis.
The Streets module analyzes signalized intersections, urban streets, and interchange ramp terminals as before, with new capabilities for travel time reliability and alternative intersections. Travel time reliability facilitates the analysis of hundreds of scenarios expanded from a single base file to generate a distribution of results for variable demand, weather and incidents with specific runs for work zones and special events – computing several performance measures, including travel time index and reliability rating.
Alternative intersections provide for the analysis of Median U-Turn (MUT) with stop-controlled U-turns; Restricted Crossing U-Turn (RCUT) for signalized, stop-controlled or fully merging U-turns; Displaced Left Turn (DLT) with signalized crossovers; and Diverging Diamond Interchanges (DDI) is under development with plans to release in February after the TRB Annual Meeting.
The Roundabouts module includes the updated capacity equations that reflect the latest research and increase capacity for all scenarios – significantly in most cases. Roundabout segment analysis is under development with plans to release in February 2017 after the TRB Annual Meeting. There were no appreciable changes to the Two-Way Stop Control (TWSC) or All-Way Stop Control (AWSC) modules beyond the upgrades to the new architecture and expansions provided in HCS 2010 Release 6.
The Freeways module now provides for segment and facility analyses within the same environment to maximize flexibility and efficient use. Procedural additions include modeling managed lanes (for continuous access, buffer and barrier designs); new truck procedures (with updated passenger-car equivalents for tractor trailer and single-unit truck mix); capacity and speed adjustment factors (for weather, incidents and driver population); revised speed flow curves (to restore interpolation for specific free-flow speeds); cross-weave analysis (for on- and off-ramps near managed lane access points); and density computed across all lanes in merge and diverge analyses.
The Multilane module implements the expansion of free-flow speeds to 65 and 70 mi/h curves; accommodates density of 45 pc/mi/ln as the LOS E/F boundary; and incorporates the new truck procedures.
As with all past versions, HCS7 is available for free download to all users with a current HCS support subscription. HCS 2010 data files are upwardly compatible for opening in HCS7.
For more information, contact Bill Sampson, PE, at bsampson@ufl.edu.