WayCast — Privacy Policy
WayCast warns drivers about flooded roads and railway crossings in India, Nepal and Bhutan. It also builds a shared map of where water collects, from measurements contributed by the phones that use it.
This policy describes exactly what leaves your phone. It was written by reading the app's own code, not from a template.
What stays on your phone and never leaves it
- Your route. The trail of positions your phone records while you drive is never uploaded. There is no code that sends it and no place to receive it.
- Your speed and your timings. Removed before anything is sent, so a journey cannot be reconstructed from what arrives.
- The first and last 150 metres of every drive. Deleted on the phone before anything is prepared for sending. Those are the metres that would show where you live and where you work.
- Your height above sea level. Only the rise and fall of the road relative to that one drive's own average is sent. Nothing absolute.
- My places. The places you save to keep an eye on are kept on the phone and never sent to WayCast. To show their weather, the phone asks the weather service for each place's forecast, as described under "Other services the app contacts".
What is sent, if you agree to contribute
| What | Detail |
|---|---|
| Road shape | One height reading per 20-metre stretch of road, given as metres above or below that drive's own average. Collected only while you are driving with WayCast open. |
| Position of each stretch | The latitude and longitude of each 20-metre stretch, so the reading can be placed on a road. Endpoints of the drive are already removed. |
| How the height was measured | Whether it came from the satellite receiver, the barometer, or both. |
| Rainfall | The rain recorded in the area over the previous 24 hours. |
| When | The month only — for example 2026-09. Never the day
or the time. The season governs how a road drains; the particular
Tuesday would only say who was driving. |
| A random code | A code such as obs-k3n8vq2p, generated at random on your
phone the first time you use WayCast. It is not derived from your
phone, your SIM, your Google account or any advertising identifier,
and it is not linked to you. It exists so readings from one drive can
be grouped together. |
| Region | The district or state the reading was taken in. |
Reports you choose to send
In the Report tab you can choose what you are reporting (water on the road, rain, a traffic jam, a bad road, road works, a blocked road, a new bridge or one being built, a warning that turned out wrong, or anything else) and, tapping it sends it at once; Other asks you to describe it in your own words first and sends it when you press Send. A report is sent to WayCast whether or not you have agreed to contribute drives, because tapping it is your choice to send that report. It carries: what you chose, your description if you wrote one (up to 300 characters), where the phone was at that moment, the time, your random contributor code and the region. Please do not write names, phone numbers or anything personal in the description. Nothing else is sent with it, and nothing is sent until you tap it.
You can also choose About the app to send a review or a request to the people who make WayCast. That carries your words, the app version, the day and your random contributor code, and no position. Reviews are read only by the WayCast team, to decide what to improve.
Reports and reviews are kept on the WayCast server. Descriptions are read by the WayCast team and are not shown to other users. They can be deleted on request like any other contribution (see below).
Why it is collected
For one purpose only: to find the dips and hollows where water collects, so that WayCast can warn a driver about a causeway or underpass they have never driven before. Contributed measurements are used to build that shared map and for research into flood risk on roads and railways. They are not used for advertising, not sold, and not shared with any other company.
The daily count of users
To know how many people use WayCast, and roughly where, the WayCast server keeps a count for each day. Nothing new is sent from your phone for this. The server counts the requests the app already makes: when it opens, when it checks for a newer version, and when it asks for map data.
Each request is turned into a scrambled code made from the network address, the type of phone or browser, and a secret number that the server makes at the start of each day, keeps only in its memory, and throws away at the end of the day. The code cannot be turned back into your address, and the same phone gets a different code the next day, so no one, including us, can follow a person from one day to the next. Only totals are written down: the number of users that day (by Android app, iPhone or iPad, and browser), the number of times the app was opened, and the number of users in each square of one degree of latitude and longitude (about 110 km) whose map data was asked for. The exact position your phone sends with a map request is cut to that square at once and never stored. The counts stay on the WayCast server and are not shared with any other company. The server also adds up, for each day and in total since the start, the kilometres of the drives that people have chosen to contribute, measured from the road stretches it already receives; a drive that is not contributed is not counted, because nothing of it is sent. They may be reported, as totals only, in research about WayCast.
Permissions, and what each one is for
| Permission | Why |
|---|---|
| Location (precise) | To tell you about water on the road ahead of you, and — if you contribute — to place road measurements on the right stretch of road. |
| Location while running in the background (foreground service) |
A phone on a dashboard spends the drive with its screen off. Without this the recording stops the moment the screen dims. WayCast shows a notification for the whole time it is recording, so it is never running unseen. WayCast does not request the separate "background location" permission and cannot track you when it is closed. |
| Notifications | To show the recording notice, and to warn you when you approach water. |
| Internet and network state | To fetch maps, rainfall and warnings, and to send queued contributions when a connection returns. |
Other services the app contacts
To draw maps and fetch weather, WayCast requests data from outside services, including OpenStreetMap, its Overpass and routing services and OpenFreeMap, open weather and rainfall archives, and public satellite imagery archives. When your phone requests a map tile or a forecast, those services receive your device's IP address and the area being requested, under their own privacy policies. WayCast sends them no identifier of its own and tells them nothing about you.
Field work files and your own places
A KML or KMZ file of stations or places that you open in WayCast is read on your phone and kept only there. The ticks, descriptions, track log and today's start point that you add during field work also stay on your phone. None of it is sent to WayCast. It leaves the phone only in a file that you choose to download and share yourself. "Remove stations" and "Delete track log" erase it from the phone.
To draw the names and roads over the satellite picture, and to find the villages, hills, temples and other places around your stations, the phone requests map data from OpenFreeMap (built from OpenStreetMap) and from OpenStreetMap's Overpass service, for the area being looked at. To find a path to a station, it asks OpenStreetMap's routing service for the way between two points. As with every map service, these receive your device's IP address and the area requested, and nothing else from WayCast.
Hospitals, hotels, shops and other places in each town are read from files on the WayCast server, built from Overture Maps (data © Overture Maps Foundation, CDLA-Permissive-2.0) and OpenStreetMap. The phone fetches the files for the area round you and round the map, and keeps them for offline use. The search itself is done on the phone.
A place that is on no map, such as a clinic or a house you are going to, can be marked from the search with a tap on the map, or anywhere with a long press on the map or with "Mark my place", with a name and a note. It is kept on your phone with your own places and is never sent.
A phone and a car screen together
So that a phone and a car screen (or a tablet) can find each other, every WayCast device tells the WayCast server, every 15 seconds, a random code made on the device and the device's model, and nothing else. The server tells it which other WayCast devices reach it over the same internet connection, such as a car screen on the phone's hotspot. Two devices are linked only when each has said yes once. While they are linked, each sends the other, through the server, its position, its barometer reading, and any route, place or warning, so that one can use the other's GPS and barometer. This is held in the server's memory only, never saved, and forgotten two minutes after the devices are last heard from. Two devices can also be linked by typing one screen's six-digit link code on the other. Once two devices have been linked, each also sends its position every 15 seconds while WayCast is open, so that they find each other when they reach the server over different connections; the server links them only when the two are within 1 km. "Link by itself" in Settings can be switched off, and "Forget linked devices" undoes every yes.
Seeing your vehicle from home
A car screen can let the phones it is linked with see the vehicle from anywhere, in WayCast only. This starts only when someone switches on "Let my linked phone see this vehicle from anywhere" on that car screen, and while it is on, the car screen always shows "Location shared with your linked phone". The car screen then sends its position, locked with a key that only the linked phone holds. The two devices make that key between themselves while they are linked; the WayCast server passes on only the public half of each device's key and can never work out the key itself, so it cannot read the position. The server keeps only the latest locked position for each car, in its memory only, never on disk, and forgets it 24 hours after the car was last heard from. Switching the setting off, or "Forget linked devices", stops it at once.
Place names you add
When you add the name of a village, hill or river on the map, it is public: the name, its kind and its position are sent to WayCast and shown to every user, who can correct it. A code that changes on every installation goes with it, so that one person's additions can be told apart, but nothing that identifies you. Names of houses, addresses, phone numbers and web links are refused. The WayCast team may correct or remove any name.
Offline first
WayCast exists because networks fail during floods. Contributions wait on your phone and are sent when a connection returns. Nothing is uploaded at the moment you record it.
Security and where data is held
Everything is sent over an encrypted HTTPS connection. Contributions are held on a server operated by the WayCast project in India. The key the app carries can only add new rows — it cannot read, change or delete anything, so the app on your phone can never read back another contributor's data.
Keeping, and deleting, what you sent
Contributed road measurements are kept indefinitely, because the value of the map is that it accumulates. They carry only your random code.
To have your WayCast data deleted (WayCast, developer Dhananjay Sant):
- Open WayCast, go to the Settings tab and open Contribute to the shared library. Note your contributor code shown there.
- Email waycastinb@gmail.com, with the subject "Delete my WayCast data", quoting that code.
- Within 30 days, everything carrying that code is removed: the road measurements (the height readings, how they were measured, the rainfall and the month) and any reports sent with it.
What is kept: the daily totals already counted (the number of users and kilometres for each day). They hold no code and cannot be linked to you or to your phone. Your email is used only to reply to you.
Because that random code is the only link between you and what you sent, it is the only way your data can be found. Clearing the app's storage or reinstalling gives your phone a new code, and anything sent under the old one can no longer be traced to you by anybody, including us.
Children
WayCast is a road safety tool intended for drivers. It is not directed at children and collects nothing that would identify one.
Changes
If what the app collects ever changes, this page will be updated and the date at the top changed with it.
Contact
WayCast · waycastinb@gmail.com