RadiusMapperDefinition
Travel-time map
Also known as: Travel-time radius, Reach map, Time-distance map
A travel-time map visualizes all locations reachable from an origin within a given time, using the shape of an isochrone rather than a distance circle. The generic term covers driving, walking, cycling, and transit modes.
Travel-time map is the general-purpose name for any map showing an isochrone polygon. It is the term consumer tools and the public use when they want to describe the output without using 'isochrone' (which sounds technical) or 'drive-time polygon' (which sounds like GIS jargon). Travel-time maps answer questions like 'how far can I drive in 30 minutes?' or 'what can I reach by bike in 15?' They can be generated for any mode and any time threshold, and are the user-facing output of most isochrone APIs.
Key characteristics
- Mode-agnostic: works for driving, walking, cycling, transit, or mixed modes.
- Time-based rather than distance-based — the input is always a number of minutes.
- Shape follows the real network for the chosen mode.
- Can be rendered as a polygon, heatmap, or contour series (5-10-15 minute rings).
- Supports overlay with demographics, competitors, transit, or any spatial data.
Common use cases
- Commute planning ('everywhere within 30 minutes of my office')
- Real estate search ('homes within 45 minutes of downtown')
- Site selection ('locations within 20 minutes of 50,000 customers')
- Accessibility and equity research
How it compares to related terms
Frequently asked about travel-time map
How do you make a travel-time map?
Pick an origin (address or geographic point), pick a transport mode (driving, walking, cycling, transit), and pick a time threshold (15 minutes, 30, 60). An isochrone engine expands outward from the origin on the mode's network, stops when the time is spent, and returns a polygon of the reachable area. You then render the polygon on top of a basemap.
What is the best travel-time map tool?
It depends on what you're optimizing for. For free consumer use: RadiusMapper, TravelTime. For developer APIs: Mapbox Isochrone API, HERE Isoline Routing, ESRI Service Area Solver. For academic or custom work: OpenTripPlanner, OSRM. For quick prototypes, a no-code tool with shareable URLs beats an API.
Are travel-time maps accurate?
Accuracy depends on three things: the road network's completeness, the per-segment speed data quality, and whether traffic is factored. Modern commercial engines using Mapbox, HERE, or Google routing are highly accurate in developed markets. Free tools using OpenStreetMap are good in dense cities but weaker in rural areas where OSM coverage thins.
Can a travel-time map combine driving and transit?
Yes — multimodal travel-time maps combine modes like 'walk to transit station, ride rail, walk from destination station.' These are harder to compute (transit schedules add a time dimension) and are typically available in more advanced tools. Most consumer travel-time maps are single-mode.