A place you can see, four kilometres away

Divided roads move traffic along a corridor and cut the people beside it off from each other. Nobody measures that cost. This does — from open data, with the method published so any claim can be checked, including the parts still wrong.

12,585

Points measured

2.2–3.8×

Beyond the ring road vs the core city

Areas ranked

Routes verified on the ground

The gradient holds under every filter we tried

The detour index is how far you must drive to reach a point directly across the road. An index of 40 means forty times the straight-line distance. Crossing a road beyond the Outer Ring Road costs between two and four times what it costs in the core city, depending on how severely the data is filtered. It narrows under correction. It never disappears.

Treatment	Core	Beyond ORR	Ratio
No correction	18.02	51.38	2.85×
Drop routes over 10 km	17.91	46.61	2.60×
Drop routes over 5 km	17.41	38.00	2.18×
Literal crossings only, under 25 m apart	24.05	92.42	3.84×
Share of points above index 50	20.4%	50.6%	2.48×

Worst areas measured

Area	Severity	Index	To cross	Points

Areas with fewer than thirty measured points are computed but excluded, because a median over a handful of points is noise rather than a finding.

Read the ranking, not the numbers. The open map under-records small connections — median openings and service roads drivers use daily are often missing. That inflates every absolute figure here by an unknown amount. It affects all areas alike, so comparing one to another holds, while individual values do not yet.

Where a typical route runs past ten kilometres to cross twenty metres, a hole in the map is the likelier explanation than a real detour, and the row says so. Those are the first places we go back and correct the map.

How it is measured

Take a point on a road modelled as two separate carriageways.
Find the nearest point on the opposite carriageway, checked to be genuinely across the road rather than a flyover overhead or an unrelated street.
Ask the road network for the shortest legal driving route between the two.
Divide driving distance by straight-line distance.

What it does not measure

Travel time

Distance and geometry only. Congestion and roadworks are deliberately excluded — a median still stands when the construction ends, and that is the claim worth making.

Walking

The open map holds 407 pedestrian crossings and 212 footbridges for a metropolitan area of roughly ten million, and none within 400 m of Abids or Secunderabad station. Absence in the map is not absence on the ground, so every claim here is about driving.

Intent or blame

We publish what an authority recorded and what we measured. Never what we think that means about anyone's motives.