How We Build Our Practice RoutesOur data sources, our methods, and their limits
Where our data comes from
Every number on our office pages comes from published data. We don't make up figures, and if we don't have something, we leave it out.
Roads and junctions
OpenStreetMap, a free map built by volunteers: road types, lanes, speed limits, traffic lights, stop signs, turn lanes, horse trails and schools within 2 miles of each office.
Crashes
The California Crash Reporting System, published by the California Highway Patrol on data.ca.gov. We use the most recent five full years.
DMV offices
The DMV's own office locations dataset on data.ca.gov, for names, addresses and map positions.
Test rules
The California DMV Driver Handbook, its Driving Test Criteria sections, Fast Facts FFDL 22, and the drive test score sheet, form DL 32.
Each office page shows when its data was last downloaded.
How we build the practice routes
We plan three loops that start and finish at the office, routed on the real street network:
- Stage 1 keeps to quieter streets, for early practice.
- Stage 2 focuses on traffic lights and stop signs.
- Stage 3 brings everything together in a test-length drive.
Turn-by-turn directions, turn counts and the lights and stops along each loop are worked out from the map data. Drive times are our estimates: we assume you drive a little under the speed limit and add time for each set of lights and each all-way stop.
These are practice loops we designed. They aren't the DMV's test routes, which the DMV doesn't publish. Routes recorded from real tests are in the Driving Test Routes app, which we're an affiliate of.
Where a test can go
We work out how long each road takes to reach from the office and shade the map in bands. Because a test starts and finishes at the office, the closest roads are the ones you're most likely to drive.
Junctions worth practicing
We count crashes recorded at each junction (within 50 feet of it) on local roads over the last five full years. Freeway crashes are left out, each crash is only counted once, and we tidy up spelling differences in street names. Some crash records have no location, so local totals are a minimum.
Lane guides
Lane diagrams come from the turn-lane markings in the map data. We only show junctions where those markings have been mapped.
What to bear in mind
- Maps have gaps. Volunteers map some areas in more detail than others, so a stop sign or crossing can be missing. Always follow the signs on the road.
- Roads change. New lights, road works and lane changes can appear before the map catches up.
- Crash records aren't perfect. Officers enter locations by hand, and some records are incomplete.
- Rules can change. We summarize the DMV's rules in plain English, but always check the DMV's own pages before your test.
- We're not the DMV. We're an independent site, not affiliated with or endorsed by the California DMV.
Who runs this site
Learn to Drive California is run by Aston Creative, an independent developer. We're an affiliate of the Driving Test Routes app and earn a commission if you subscribe through our links. That doesn't change our practice routes, guides or data.
Want the routes from real tests?
The Driving Test Routes app has routes recorded from real tests at California DMV offices, with turn-by-turn voice directions. Your first week is free.
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Spotted a mistake?
If something on a page is wrong, such as a missing stop sign, a closed road or an outdated rule, email us at info@astoncreative.com and we'll check it.