Elevation accuracy on long routes

When planning long routes on the website, cycle.travel speeds up your route calculation by not showing turn-by-turn directions. This has a side effect of making the total ascent/descent calculations less accurate. You can improve accuracy by clicking ‘Show turn-by-turn directions’ on the left.

Comparing elevation across sites/devices

Calculating the total climb of a ride is notoriously difficult.

cycle.travel, like most route-planners, uses a worldwide grid of elevation data. When it’s calculating the elevation for a route, it looks up each point on a grid, and works it out by averaging the nearest points. It then calculates out the amount you’ll climb over the course of your ride by looking at the elevation difference between points.

Sounds simple? If only. On its own, this method leads to a lot of little fluctuations that aren’t reflected in the road/path you’ll ride. It doesn’t take any account of tunnels or bridges, where you’re not riding at ground level. And in areas where the road follows a steep-sided valleys, like the Alps, it can sometimes appear that the road is further up the hill than it actually is – causing lots of little ups and downs that aren’t there.

cycle.travel does a lot of extra calculation to minimise these effects and make the total figure more accurate. We think our figures are among the most accurate there are. But because different route-planners (and GPS units) use their own calculation methods, comparing figures from two sites will invariably result in a discrepancy. We’d suggest that you use the total climb as a guide to determining which of two cycle.travel routes will be the hilliest, rather than as a gospel fact.