Rendering bridges correctly for 3D terrain

Motivation

When enabling a 3D terrain effect using map.setTerrain(), things look beautifully realistic until you check out some road bridges, where the terrain dips and the road follows the terrain instead of rendering as a straight bridge.

Design

It would be super neat to see sections of roadways, railways, and pedways that are marked as bridge sections to have an elevated, straight way that connects to the terrain surface at the ends of the bridge.

Mock-Up

Apple Maps detailed city experiences "DCEs" do something to this effect, and it really completes the 3D experience, especially when combined with custom 3D models for significant bridge structures:

Implementation

I don't know enough of your codebase to know if this is feasible within the current architecture, but if so I think it would be an excellent addition to the ultra-realism and detail that Mapbox provides!

Begin at the map.setTerrain() entry point and trace how terrain affects road, railway, and pedestrian-way rendering. Define how bridge-marked sections would stay elevated and straight while joining the terrain surface at each end, then validate the result against the supplied bridge examples.