Known limitations

Everything below is known and written down. If what you found is here, there is nothing to report — though a note is still welcome. If it isn’t, report it: a case nobody has seen is worth more than a case already filed.

The list is gone through at every release, so it says what is still open today.

What the app is not

It is not navigation: no turn-by-turn, no destination, nothing to read while the car is moving. It records where you have been and says what that adds up to.

It does not meter your pavement either. Credit is exit to exit in reference miles, so the figure for a drive is not the figure on your odometer.

The map

Two Baltimore tunnels are missing. The road data stops at one portal and resumes at the other, with nothing between, so I-95 in Maryland measures about half a mile short and I-895 about 0.9 miles short. A stop on one side of a tunnel also cannot be joined to travel on the other, because the app treats the gap as a real break in the road.

Thirteen sections carry no exits. An exit is attributed to a route only through that route’s Interstate route relation in OpenStreetMap, and an unsigned designation has none. I-595 in Maryland — signed as US 50 and US 301 — is the largest: 25 real interchanges, none of them visible to the app. A section with no exits is a single stretch end to end, so it is all or nothing.

Divided highways are one averaged line. Where the two carriageways run far apart the line sits between them. Southbound I-95 north of Baltimore runs more than 100 meters from it, far enough to break the match; the app then closes the hole and credits the stretch as bridged rather than GPS-verified. The miles are right and the provenance is pessimistic.

Hawaii’s directions are wrong in trip history. I-H1 and I-H3 run east and west, and Hawaii’s numbering does not follow the mainland’s odd-north, even-west convention, so a drive on them is labelled north or south. Only the label is wrong; the miles are not.

The matcher

A frontage road can be taken for the Interstate. On I-97 in Maryland, two drives on Veterans Highway — a surface road running 40 to 80 meters west of the highway — were credited to I-97, about 1.3 miles each. The app’s map carries Interstates and nothing else, so there is no better road for a trace to lose to, and real driving on a wide median already sits tens of meters off the line. A tighter distance gate would reject genuine Interstate driving, so this one is open rather than patched.

Losing GPS leaves a gap. A short gap inside one run of travel is closed when the road runs through and the travel on both sides shows the drive continued. A long one is left as a gap rather than guessed at, which is why a tunnel you sat in for ten minutes can cost you that stretch.

The live card

The live card can say nothing on a drive that credits new road. On one recorded drive it announced none of the four new stretches, while the finished trip recorded all four. The trip record is the durable one and it was right. The live path is the part that failed, and it has no logging of its own yet to say why. If your card stays quiet on a drive that fills the map in afterwards, this is that.

The card is also always a few seconds behind: it needs several agreeing fixes before it will name a road, and it catches up every 15 seconds while it is on screen.

Platforms and files

Android only. iOS is planned and does not exist; there is nothing to install and no way to join a test for it.

Android Auto is unverified. The app declares a car pane, but it has not been confirmed on a real head unit and Google has not been asked to distribute the app to cars. If it never appears in your car’s app list, that is expected.

GPX is the only way in. No other app’s export can be imported, and a JSON export from the app cannot be imported back.