This mode would prioritize paved roads (by quality), presence of a bike lane, and road width (if a bike lane isn't available, a wider road might be safer than a narrow road).

Data captured in tiles must be different from Gravel Cycling.

The original system of loading tiles as needed is good, but the implementation relied on the tiles being numbered by integer indexes. This made downloading data for specific cities clumsy, as the tiles had to be downloaded sequentially. The new tiling system introduced coordinate-based tile numbering, so tiles could be saved without relying on already existing tiles.

This change requires the graph-building method to find the needed tiles by coordinates instead of by their integer-based index.

When returning a generated route, we need to include additional route information like the duration, distance, and other metrics. An alternate route can also be returned, calculated using a different weight.

Currently an area of only 40km around Waterloo is available. Implementing a tile-based system would help expand coverage and should still be fairly resource-light since only needed tiles can be loaded.

Currently the alt route is calculated using an entirely different weight function, giving a route that doesn't always comply by the user's chosen preference ("gravel cycling" selected but route includes only paved roads).

Instead, we should be using the same weight function while filtering out roads already used in the previous route. This would give another route that still matches the preference while being different from the first-shown route.