gig-line/Geo/verification/2026-11-06-street-profile.md

Street profile — Hollywood Blvd block

Measured 2026-11-06 from the block extract (Geo/raw/osm-api-map-2026-11-06.osm) with Geo/tools/street_profile.py. Reproduce with:

python3 Geo/tools/street_profile.py Geo/raw/osm-api-map-2026-11-06.osm

All distances are metres, computed on a local planar approximation at the block's mean latitude (error well under 1 cm over 300 m). OSM is layout data; these are geometry measurements, not a survey.

Boulevard

• Centreline between Orange Drive and Highland Avenue: 279.4 m, 9 vertices.
• Posted speed 25 mph, lanes=4 on the block segments, surface=asphalt, sidewalk:both=separate (sidewalks mapped as their own ways).

Crossings across the boulevard

Three signalised crossings, measured as the length of the crossing way:

OSM way	Across the road	Position along block	Markings	Notes
385648318	24.4 m	36.6 m	yes	at Orange Drive; widened by the junction
385648319	20.9 m	130.1 m	yes	mid-block, just west of the hero frontage
385648320	25.9 m	266.1 m	not tagged	at Highland Avenue; junction flare

Crossing endpoints sit within about 1 m of the kerb line, so these lengths approximate the carriageway width, not the full road reserve. Other footway=crossing ways in the extract cross other streets or lead along the boulevard; they are filtered out.

Sidewalk and frontage

Mapped sidewalk centrelines sit 12.6 m (south) and 13.6 m (north) from the road centreline. Building setbacks, measured to each building's nearest vertex:

Side	Building	Setback	Frontage extent
S	6922	14.6 m	66.1 m
S	6902	14.5 m	31.0 m
S	6840 El Capitan Entertainment Centre	14.5 m	25.7 m
S	6838 El Capitan Theatre	14.8 m	38.6 m
S	6822 Budget	13.8 m	6.2 m
S	6806–6820	13.0 m	33.1 m
S	6800 Lee Drug Building	14.9 m	19.0 m
N	6925 TCL Chinese Theatre	15.7 m	44.0 m
N	6933 Madame Tussaud's	15.8 m	42.0 m

Derived widths

Using the mid-block crossing (20.9 m across) as the carriageway width, half-width is 10.45 m:

• South sidewalk: 14.5 − 10.45 ≈ 4.0 m.
• North sidewalk: 15.7 − 10.45 ≈ 5.3 m (measured to the Chinese Theatre, which sits behind its forecourt, so this is an upper bound).

Cross-check: a 4.0 m sidewalk between the kerb at 10.45 m and the hero frontage at 14.5 m puts its centreline at 12.5 m, against 12.6 m measured. The arithmetic is consistent, which is why these figures are usable despite nothing being tagged with a width.

Discrepancy to record

lanes=4 with a 20.9 m carriageway implies 5.2 m per lane. That is not a plausible lane width, so one of these is true: parking or turn lanes are untagged, or the crossing overstates the kerb-to-kerb distance by a metre or two. Do not derive lane counts from the width or width from the lane count until this is settled against the reference photographs. It does not block the demo: the crossings and setbacks are measured independently of the tag.

Designated crossing for 0.1.0

Use the mid-block signalised crossing, OSM way 385648319, at 130 m along the block. It is about 4 m west of the hero building's west corner, so it is the crossing a player naturally uses to reach the El Capitan Entertainment Centre frontage from the north side. The alternative at Orange Drive (36.6 m) is at the block corner and 24.4 m wide; Highland (266.1 m) is the far junction.

Still open

• The lane-width discrepancy above.
• Kerb height, kerb radius at the crossings, and any sidewalk obstructions — not in OSM.
• Road surface slopes and elevation, pending the DEM decision.