The policy review module checks roadway-segment design elements for compliance with relevant highway geometric design policies. The module provides electronic files replicating quantitative policy values specified by the American Association of State Highway and Transportation Officials in the 1990, 1994, and 2001 editions of A Policy on Geometric Design of Highways and Streets and automates checks of design values against those policy values. IHSDM also provides a tool for inputting policy tables from other agencies' design policies.  See the WSDOT policy adjustments.

The module organizes checks into four categories: cross section, horizontal alignment, vertical alignment, and sight distance. Cross-section checks include through-traveled way width and cross slope, auxiliary lane width and cross slope, shoulder width and cross slope, cross slope rollover on curves, clear zone and roadside slope, normal ditch design, and bridge width. Horizontal alignment checks include radius of curvature, superelevation rate and transition design, length of horizontal curve, and compound curve ratio. Vertical alignment checks include tangent grade and vertical curve length. The policy review module also can check stopping, passing, and decision sight distance.

This module can be applied at several stages in the highway design process. During project planning and scoping for improvement projects on existing roadways, it can provide an initial assessment of how the existing geometric design compares to current design guidelines. For all projects, it can facilitate quality assurance checks throughout detailed design and design review.

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