As long as it only pulls data and doesnt share any its not as bad. But each of these local services most likely use different APIs and formats, so implementing it wont be so easy. For just large highways its realistic imo, but if you want data for inside cities it becomes impossible.
If the database of traffic info become so large that it's impossible to download it all at once it means you have to selectively download data for your location/route which makes it possible to infer user location again.
Oh okay, that wasnt very obvious. This would have worked better.