Curb

Why this pattern exists

The curb is the single most foundational physical element separating modes on a street; its height, material, and continuity determine drainage behavior, accessibility, and how legible the vehicle/pedestrian boundary reads to everyone using the street. Nearly every other Element pattern in this family (extensions, ramps, cuts) is a modification or interruption of this base condition, so it needs its own definition first.¹

Key considerations

• Height should be sufficient to discourage casual vehicle encroachment onto the sidewalk while not creating a tripping hazard where pedestrians cross it
• Material and profile should be durable against snowplow damage in climates where that applies
• Continuity matters: an interrupted or inconsistent curb line undermines drainage design and the clarity of the mode boundary

Related patterns

Curb Extension (ELM-CBE-02), Curb Ramp (ELM-CRP-03), Curb Cut/Driveway Apron (ELM-CCA-04) (all modifications of this base element); Crosswalk (ELM-CRW-08) (a common interruption point)

References

1. Precedent-based Federal Highway Administration, Designing Sidewalks and Trails for Access, Chapter 4, Section 4.4.11 ("Roadway Design"). Curb height and material guidance by roadway functional class (Table 4-1).