Route Segmentation

[Pete-Y-CS]

In looking at the LCWIPs I have encountered several with segmented routes. For example West of England Combined Authority has most of its routes split into segments with some description of what will happen to each segment:

This also include in places alternatives where the route could go one or more ways depending on future information. There is also the question of pre-existing infrastructure. So we might have a route which is conceptually 1 route, but has multiple segments of different styles of path, that might be existing, or new, or existing but to-be-upgraded.

So I think there is a need for us to consider the UX and data format required to capture these sorts of things. We should be able to define a route and segments of that route. We should also allow for segments to be optional with alternatives.

This raises another question of conceptually distinct routes which share segments with another route. This is nicely exemplified by an example in Peterborough where there are 3 routes noted which all share the majority of their route, as seen here:

So additionally we may want to support segments being shared by different routes. At the very least a way to visually show multiple routes along the same path might be necessary.

All of these probably want some discussion with Sustrans and ATE folks with more experience in the field.

[dabreegster]

In the first WECA example, somebody could individually map each of those segments and fill out the descriptions, or map one big long piece, use the split tool, and fill out the description for each segment.

Per segment, maybe we have a "is this the preferred/main option or an alternative?" question. Do we need to ask people what it's an alternative to or fill that out in the data, or can we can figure it out later manually or algorithmically?

For the last shared segment question, can we just map the shared segment once and describe it adequately? Is the problem that it might belong to multiple sub-schemes at a time?

In general, can we ask people to map segments exactly once and fill out enough detail on them? Do we need as output any concept of the full route, or can we stitch that together by joining adjacent segments?

[Pete-Y-CS]

These are all great questions and I'd rather ask ATE folks and the people who are gonna be mapping what they reckon than answer them myself 😅

[dabreegster]

In a call with Robin, Katie, Andre, and I, I think we're settling on the approach of just mapping the entire route as one object, then mapping the entire alternative, and ticking a checkbox to indicate it's an alternative. No splitting or figuring out common segments. This lets us calculate the metric of total length of the planned network by just filtering out is_alternative=false, and reduces the decisions the mapper has to make about where/how to split.