The app itself can only watch your location while it's open on screen. For an alert that fires even with your phone locked in your pocket, use your phone's own built-in location automation — free, and already installed. Follow the guide for your phone below.
iPhone Using Shortcuts
Open the Shortcuts app (built into every iPhone — look for the coloured icon with interlocking squares).
Tap the Automation tab at the bottom, then tap + in the top corner, then Create Personal Automation.
Choose Arrive. Tap Location and search for the bridge (use the coordinates in the table below — paste the numbers into the map search box). Set the radius to around 200 metres. Tap Next.
Tap Add Action, search for Show Notification, and type something like "Approaching Warburton Bridge — remember the toll." Tap Next.
Turn off "Ask Before Running" so it fires automatically without needing you to confirm. Tap Done.
Repeat for each bridge you want alerts for. It only takes a minute once you've done the first one.
Optional extra step: in the same automation, add a second action Open URL and paste in your site address (e.g. tollbridgeuk.com) so the app opens itself and starts logging the crossing automatically.
Android Using Google Maps
Open Google Maps and search for the bridge using the coordinates in the table below.
Tap the location pin, then tap the three dots or Save, and set a location reminder — Maps will alert you when you're nearby.
If your phone doesn't offer this directly in Maps, use the Google Assistant app instead: say or type "Remind me when I get near [bridge name]" and confirm the location.
Repeat for each bridge. Reminders stay active until you delete them, so this is a one-time setup per bridge.
For a more powerful setup (custom sound, auto-opening the app, works even if Assistant reminders are flaky on your phone model), the free app Tasker with its "Location" context can do the same job as Shortcuts does on iPhone — worth it if you want it rock solid.
Bridge coordinates
Use these to search for each bridge when setting up your automation.