Horizontal Alignment Tool

Tap the map to place three points on the road centerline.

Select the Point of Curvature (PC), midpoint on curve, and Point of Tangent (PT).
Drag a marker to refine; red tangent lines should align with the centerline.
Target 30–120° separation on the constant-radius portion.
Only use with circular curves (avoid spirals).
The MDOT advisory speed is for Full superelevation ONLY
Mobile: pinch to zoom. Desktop: Shift+drag for box zoom.

Inputs

Roadway type

Roadway surface

AADT category

Need counts? SEMCOG Traffic Volume Map

Posted Speed (mph)

Advisory Speed (mph) from Ball Bank Study

Road width (ft)

Height (ft)

Chevron placement mode