ADA Ramp Surveys in Benicia, CA

Benicia’s First Street historic district is the accessibility challenge in this city, and it is a genuinely hard one. The downtown grid dates to the 1840s, the buildings along First Street run from the Carquinez Strait waterfront up through the commercial blocks, and the street itself falls toward the water. That combination produces the classic historic-downtown conditions: raised entries with a single step, thresholds that were never dimensioned, storefront floors set to nineteenth-century sidewalk grades, and walk panels that have been cut and patched around a century and a half of utility work. Add the downtown parklet and streatery program, which places dining structures in the public right of way, and the accessible route through a block becomes something that has to be checked as built rather than assumed from a plan. The City maintains an ADA Transition Plan, a designated ADA Coordinator, and a published grievance procedure, and Measure F street funding is now supporting street and sidewalk repair work.

Where a route is this constrained, the design lives or dies on real numbers. A sidewalk that falls with the street can still hold 1:48 across the walk, but only if the designer knows to a hundredth where the existing surface is. We measure the frontage as a surface: dense scan or total-station observation tied to survey control, so cross slope is computed across the actual panel, the running slope of the walk is known block by block, and threshold and door landing elevations are measured rather than estimated. Parklet decks get the same treatment, since the accessible route past and into them is what the standards care about.

Deliverables include cross-slope maps along the frontage, per-ramp and per-entry slope exhibits, spot elevations at every threshold and grade break, and CAD. Solano County records for Benicia run through the County Recorder and County Surveyor in Fairfield. See also Benicia as-built surveys and Benicia 3D scanning.