Isochrone Map
Travel-time isochrones along the road network for drive, bike, or walk modes.
By Aryan Khan, Founder & Editor · Updated October 2026
For example, a 30-minute drive-time polygon around a city depot covers the motorway corridor generously and the river's far bank barely — the shape roads actually allow.
How to use Isochrone Map
Reach is a shape, not a circle. Draw the true one:
The Isochrone Map draws the area reachable within a set travel time from one origin, following the road network for driving, cycling or walking. Set the place, mode and minutes and read the polygon — the honest shape of reach that a radius circle only pretends to be.
- 1Set origin, mode and times.
- 2Generate polygons.
What people use Isochrone Map for
1. Site and store location
A site is worth its isochrone. Draw candidate locations' 20-minute polygons and compare catchments as shapes — the Drive Time Map is this site's other instrument for the same question.
2. Public-service coverage
Response-time duties are isochrone duties: the polygon is the area a station can honestly claim. Population inside it is the next number, from the population tools.
3. House hunting by commute
Draw the 45-minute polygon from the office and house-hunt inside the shape, not inside a circle that includes the estuary.
4. Planning literacy
One isochrone teaches more transport geography than a chapter of text: networks, barriers and corridors are all visible at once.
Worked examples
A 30-minute driving polygon stretches far along fast roads and barely across slow ones. Two homes the same crow-miles from work can sit one inside and one outside the shape — that is the entire argument for drawing it.
The 20-minute walking polygon is a compact blob around the origin; the 20-minute driving one is a starburst along the arterials. Same minutes, different cities — mode is a geography of its own.
Isochrone or radius — which shape?
Two ways to draw reach. This page is the network column; the Map Radius Tool owns the circle column.
| Property | Radius circle | Isochrone (this tool) |
|---|---|---|
| Follows roads? | No | Yes |
| Blocked by rivers and rails? | No | Yes, as the network is |
| Depends on mode? | No | Drive, cycle and walk differ |
| Symmetrical? | Always | Never — corridors stretch it |
| Best for | Quick screens, legal buffers | Real reach and catchments |
| Data | None needed | Road network (open data) |
Isochrones are only as current as the network data beneath them; a new bridge redraws the shape the day the data learns about it.
Fifteen, thirty, forty-five minutes: see all three at once
A single travel-time ring answers one question; three nested rings answer the real one — how reach changes as you spend more minutes. This page presets the isochrone engine to 15/30/45, drawing the genuinely network-derived reachable areas as layered polygons that stretch along fast corridors, pinch at bridges and stop at barriers. The irregularity is the information: a motorway finger at forty-five minutes that doesn't exist at fifteen is a story about your city's skeleton.
These are not circles and not buffers; they come from the Valhalla routing engine tracing actual roads for the mode you choose, which is why a river with one bridge produces a comb and a grid city produces a blob. House hunters use the nesting to price commutes, clinics to picture patient access, restaurants to design delivery menus, and planners to argue about infrastructure with pictures instead of adjectives. Contours can be swapped for other presets, the polygons export as GeoJSON for reports and GIS work, and the shareable URL preserves centre, mode and times — so an isochrone, like every good map here, is a link you can send.
How to interpret the result
The most common errors come from using a correct result to answer the wrong geographic question. Keep these points in mind for Isochrone Map:
- Place route endpoints on roads, not rooftops. Routing engines snap points to the nearest drivable way, and a point in a river or a courtyard can snap somewhere surprising — nudging the pin to the nearest street makes results stable and explainable.
- When optimising many stops, keep the true origin first and let the engine order the rest; then sanity-check the result visually. Optimizers minimise distance, not your time windows — hard appointments still belong in manual order.
Limits & appropriate use
Routing's limits live in three places: data vintage, access reality and time modelling. The network is OpenStreetMap's current picture — new interchanges lag, private gates may be missing, seasonal ferries keep their own calendars. Access rules reflect mapped law, not today's roadworks. And durations are free-flow physics: speed limits and road classes without your city's sociology, so peak hours, weather and parking belong in your buffer, not in the engine's promise. The tools label all three limits on every result, because an unlabelled estimate is a trap.
What the stack does brilliantly is the reproducible core: the same stops, mode and engine give the same route to everyone, everywhere, which makes it a superb baseline for comparison, screening and planning. Escalation is domain-specific and well understood — professional dispatch adds live traffic and driver hours; logistics tenders add contracted networks; navigation products add certified maps. A free browser tool that hands you a clean, exportable baseline with its assumptions printed is not competing with those; it is feeding them.
- Live congestion and ETAs → traffic-aware commercial routing.
- Driver-hours and windows → transport-management systems.
- Certified navigation → licensed map products with update guarantees.
Data & methodology
Valhalla computes reachability polygons for the chosen centre, travel mode and up to four time contours; coverage and model assumptions affect the result.
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- Costing model
- The routing engine's mode profile (auto, pedestrian, bicycle) with its speeds and rules.
- Free-flow time
- Travel time from speed limits and road classes, without congestion.
Editorial guidance: MapBench explains the method and limitations so the tool can be used as a transparent reference, not as a black-box answer. For legal boundaries, safety-critical routing, surveying, engineering, regulated decisions or official statistics, verify the result with the responsible authority or a qualified professional.
Category: Routing & Travel Time. Results are intended for everyday analysis and planning unless a page explicitly states otherwise.
Method, assumptions & limits
- This tool’s method
- Valhalla computes reachability polygons for the chosen centre, travel mode and up to four time contours; coverage and model assumptions affect the result.
- Before relying on the answer
- Check the stop order, travel mode and whether the result is a network route or a simplified estimate. Repeat the calculation after changing any of these inputs.
- What the result cannot establish
- Road access, congestion and closures can change. An estimated duration is not a live arrival-time commitment.
Coverage: Worldwide. Search, basemap and external data requests may use third-party services; browser-based does not mean every operation is offline. Read the source and licence notes, calculation methodology and privacy policy. If a result looks inconsistent, report a correction with the inputs and mode used.
Frequently asked questions
Clear answers about the calculation, accuracy and appropriate use.
Same as drive time map?
Same engine — focused entry for isochrone workflows.
Does the route include live traffic?
Unless the tool explicitly says otherwise, travel times are planning estimates and should not be treated as live-traffic predictions.
Why is road distance longer than straight-line distance?
Roads must follow the available network, terrain, bridges and restrictions, while straight-line distance measures the geometric minimum between two points.
Can route results change over time?
Yes. Road-network data, access restrictions and routing datasets can change, so recheck important journeys close to travel time.
Is this the same as the Drive Time Map?
Cousins, not twins: both draw travel-time reach from the road network. This page is organised around the isochrone concept and its modes; the Drive Time Map around the depot-and-minutes planning workflow. The polygons agree because the network is shared.
Why is road distance longer than straight-line?
Roads wind — and isochrones exist precisely because reach follows roads, not geometry.
Which modes are supported?
Driving, cycling and walking, each on its legal network — the walk polygon uses paths a car cannot, and vice versa.
How many time bands can I draw?
Several rings at once — nested isochrones (10/20/30 minutes) are the classic catchment picture this tool is built for.
Can I export the polygon?
The reach shapes are the working output of the page; the site's export tools elsewhere handle GPX and data formats for routes.
Why is my polygon not a neat set of rings?
Because roads are not neat. Lobes along fast corridors and bites where barriers sit are the information — a neat shape would be the lie.
30-minute isochrone at 3 a.m. versus 8 a.m.?
This tool draws typical-speed shapes, closer to the free-flow case. Rush-hour polygons shrink; schedule the real trip with margin the map cannot give you.
Related tools and resources
The workflow twin is the Drive Time Map; the simple circle is the Map Radius Tool; and what lives inside the shape is listed by the Cities Within a Drawn Area Finder.
More free tools
Sources, methodology & editorial trust
- ✓ Browser-first processing where supported
- ✓ External sources are documented
- ✓ No account required for public tools
- ✓ Review data sources
Calculations are documented with their assumptions, limitations and source context rather than presented as unexplained answers.
Reviewed and maintained by Aryan Khan, Founder & Editor of MapBench.
Part of our routes & travel time hub
Isochrone Map sits in the routes & travel time cluster, alongside 62 other tools that answer neighbouring questions with different methods or datasets.
You may also need
When this answer is only part of the job, these clusters cover the next step.
Read the guide behind this tool
Reading an Isochrone Map Like a City Planner — Those lumpy drive-time shapes are the city telling you its secrets. How to read fingers, holes and lobes — and use them for real decisions.