Incorrect speed limit shown when driving over highway bridges

When driving on a bridge across the highway, Sidecar sometimes mistakenly assumes that you are driving on a highway and will show you a speed limit of highway instead of bridge road

The issue names no files, tests, or entry points. Start by reproducing the behavior while driving over a bridge across a highway, then trace how the road type determines the displayed speed limit; done means the bridge road's limit is shown instead of the highway limit.

Written by the indexing model from the issue text.