How far are you from a park?
Click anywhere in Mumbai. The shaded area is everywhere you can reach in 15 minutes — following actual streets, not a circle drawn on a map — and the dots are parks, green if they fall inside it.
Click the map to move the point. Driving uses live traffic, so the same spot answers differently through the day.
Why not just draw a circle?
Because a circle answers the wrong question. Distance as the crow flies has almost nothing to do with whether you can get somewhere in 15 minutes — a park 400 m away across a railway line with no bridge is further, in practice, than one 900 m away down a straight road.
An isochrone follows the road network instead, which is why it comes out lumpy — and sometimes full of holes. You can see one on load: a park’s interior has no roads through it, so the band has a hole shaped exactly like Shivaji Park, with your marker sitting in it. Test a park by its centre and the one you are standing in looks unreachable. This map tests park edges instead, which is where you actually walk in.
Driving uses live traffic, and in Mumbai that is the difference between a fiction and a fact. Asked to ignore traffic, the API puts a 15-minute drive from Dadar at 15.6 km — an implied 62 km/h clean across the city. With traffic it is about 3.9 km, or roughly 16 km/h. The second number is the one that matches Google’s own routing engine for the same journeys; the first was quietly assuming highway speeds on roads that have never offered them.
Because it is live, the driving answer changes through the day, and the panel stamps the Mumbai time it was measured. Walking ignores traffic entirely, so a walk band is the same at any hour. On a Sunday afternoon, 15 minutes on foot from Shivaji Park covered 0.93 km² and reached 2 parks; the same quarter hour in a car covered 8.54 km² and reached 31. Try it at 9am on a weekday and the car does considerably worse.
Reachability from the Google Isochrones API — traffic-aware for driving, which means a snapshot of the moment it was measured rather than a reproducible figure. The API accepts no departure time, so a specific hour cannot be requested; walking is traffic-unaware and therefore stable. Travel times from the Routes API. Park locations from OpenStreetMap contributors, ODbL 1.0. Outside Mumbai, parks come from Google Places.