The Federal Highway Administration (FHWA) Office of Operations Research and Development (R&D) developed the first version of Capacity Analysis for Planning of Junctions (CAP-X) in 2009, expanding on a previous release of the Alternative Intersection Selection tool.  The updated and current third version of CAP-X was developed in partnership with the Highway Safety Manual Implementation Pooled Fund Study.  As the name suggests, CAP-X is a tool that can be used to evaluate a variety of junction designs, including at-grade, grade separated, and service interchange, using given peak flow volumes. The intersections and interchanges are evaluated using the method of critical lane volume summation to provide planning capacity assessment at each crossing, and roundabouts are evaluated using the equations in the Highway Capacity Manual (HCM) (except the three-lane roundabout). The CAP-X tool was developed for use within Microsoft Excel; basic knowledge of Excel is necessary to use CAP-X. This workbook is designed to be simple, with only movement volume counts and number of lanes needed to be entered into the tool. The spreadsheet workbook includes explanatory, input, and summary sheets, as well as individual sheets for each of the analyzed junctions. As part of an Intersection Control Evaluation process, CAP-X is intended to be used as sketch-planning tool that will help users focus on more effective intersection and interchange designs prior to conducting more involved traffic analyses.

Users

Traffic Operations Engineers, Highway Design Engineers, Safety Engineers, Traffic Planners, Researchers

Contact

• Jeffrey Shaw, Office of Safety Technologies, Safety Operations Team, jeffrey.shaw@dot.gov

System Requirements

9MB hard disk space; Microsoft Windows XP, 7, or 8; Microsoft Excel 2010.

>>Download<<