This guide summarizes the MUTCD requirements and practical application guidance for the M4-9a BICYCLIST/PEDESTRIAN DETOUR sign. Use this resource to understand when it is required, how to place it correctly, and how to maintain clear visibility for safe operations.
Shared bicyclist/pedestrian detours around closures
Along the detour route at each decision point.
Mount at the standard height and setback for the roadway with clear sight lines.
High reflectivity and clear sight lines are essential day and night.
Directs both bicyclists and pedestrians along a detour route with the bicycle and pedestrian symbols, the word DETOUR, and a directional arrow (M4-9aL/M4-9aR directional versions).
Directs both bicyclists and pedestrians along a detour route with the bicycle and pedestrian symbols, the word DETOUR, and a directional arrow (M4-9aL/M4-9aR directional versions). In the field, M4-9a Bicyclist/Pedestrian Detour is typically positioned at the along the detour route at each decision point. Common deployments include shared bicyclist/pedestrian detours around closures; each turn of the detour marked with the directional arrow; used with SIDEWALK CLOSED and path-closure signing. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Along the detour route at each decision point.
Typical minimum: 24" × 12" (route marker / plaque).
Placed where a California work zone closes a shared-use path, sidewalk, or bike route and both bicyclists and pedestrians must follow a signed, accessible detour.
Go to California NotesEducational reference only. This is not an official Caltrans, FHWA, or local agency publication and is not legal or engineering advice. Always verify sign selection, size, placement, spacing, and application against the current CA MUTCD 2026, Caltrans sign specifications, Standard Plans, project documents, and the reviewing agency’s requirements. Local jurisdictions may impose additional requirements, and final selection, placement, and dimensions may require engineering judgment or agency approval. Written against California MUTCD 2026 (effective January 18, 2026) and the Federal MUTCD 11th Edition. Official sources last verified June 2026.
Public Ready supports sign selection, project-ready sign packages, and equipment sourcing through qualified providers — with expert support built for compliance.
