Built to replace the circle.

Origin

Why we exist.

The 5-mile radius circle is still the default trade-area tool at most companies. It's on every franchise disclosure document, every commercial real estate deck, every retail site evaluation model. It's also wrong — not approximately wrong, but wrong by construction.

Customers don't move in circles. They drive on roads. Roads have speeds, directions, barriers, and chokepoints. A river with one bridge concentrates all access through that crossing. A highway on-ramp lets customers reach you from 6 miles away in under 10 minutes, while a neighborhood two miles across town takes 18 minutes because of a one-way grid. The radius circle treats all of these identically.

Drive-time isochrones fix this. The technology has existed in academic GIS for decades; what changed is the cost. OpenStreetMap made the road graph free. Graph traversal on commodity cloud compute made the calculation fast. DriveZone was built in 2024 to bring the isochrone out of the GIS department and into the decision-maker's browser — no GIS skills required.

Methodology

How the polygon is computed.

Accuracy depends on the road network data and the routing algorithm. DriveZone uses:

• Road network: OpenStreetMap with nightly differential updates. OSM is the world's largest open road dataset, with coverage across 43 countries. US coverage includes surface roads, highway networks, turn restrictions, one-way designations, and ferry routes.
• Routing engine: Graph-based routing with Dijkstra-variant traversal, stopping at the time budget. The engine respects turn costs, traffic signal delays, and access restrictions — not just straight-line distance.
• Speed profiles: Historical daypart speed data by road classification — residential, arterial, highway — calibrated to US urban driving patterns. Peak (7–9 AM, 4–7 PM), midday, and off-peak profiles.
• Population data: US Census Bureau ACS 5-year estimates at census block group level. Population inside the polygon is calculated by the centroid-in-polygon method — the industry standard for trade area population counts.

Demographic data (median household income, population density, age distribution) is sourced from the same ACS 5-year estimates, updated annually when the Census releases new data.

Users

Who uses DriveZone.

Research

How accurate are drive-time maps?

We ran drive-time isochrones against 5-mile radius circles across 412 U.S. retail-relevant origins — strip centers, downtown blocks, and shopping-mall anchors. We measured the population disagreement: how different was the population count when using a drive-time polygon versus a 5-mile radius?

The results: the two methods agreed within ±5% on only 11% of origins. Disagreement above 25% was the median. Above 40% occurred at 14% of origins — almost always in coastal markets, near river crossings, or at highway interchange locations.

The implication is direct: if your site selection uses radius circles, you are working with population estimates that are wrong by more than 25% in the majority of cases. Read the full analysis →

Coverage

What we support.

Research team

Who writes the analysis.