Calculate travel demand on bus routes

Hussein-Mahfouz commented 6 months ago

Demand at the OD level is processed using issue #4 and PR #14

How do we project this demand from the OD level to the route level? Currently I am using two different methods. Take an OD pair with demand = 20 that is served by 3 routes: Route A (freq = 6 buses/hour), Route B (freq = 3/hr, Route C (freq = 3/hr):

Method 1 (All-to-all): If an OD pair has demand = 20 and is served by two direct routes, each of these routes is assigned the 20
Method 2 (Frequency-based): Demand (Route A) = Total Demand freq A / sum(freq A, freq B, freq C) = (20 6) / 12 = 10

Hussein-Mahfouz commented 6 months ago

Method 1 (all-to-all) has much higher numbers as there is redundancy - it could show what demand on route X could be if it was the only route offering a service for the ODs that it passes through.
Method 2 is a better reflection of what the actual demand is

Which method suits our purpose better?

Robinlovelace commented 6 months ago

Without much context, method 2 seems to work well, what's the downside?

Hussein-Mahfouz commented 6 months ago

This is my current (incomplete) thinking. If we are looking at which bus routes to remove, then is it better to look at:

(a) the maximum potential demand on the route (i.e. the demand that could be satisfied directly by the route if there was no other service) OR
(b) an estimate of the actual demand on the route, given the current network **
(c) an all-or-nothing approach (not done above): all demand assigned to highest frequency route only

(a) could give us a ceiling for the demand on a route, and we could combine it with another step - identifying the total demand that is uniquely* served by each route - to inform which routes are more important and which are redundant

(*) demand between A-B is uniquely served by a route X if it is the only route that goes directly from A to B

(**) Approach from chapter 10 of Modelling Transport

Hussein-Mahfouz commented 2 months ago

The multi-path approach in the last comment can be calculated using Aequilibria, see relevant documentation here

Robinlovelace commented 2 months ago

:+1:

Hussein-Mahfouz / drt-potential

Calculate travel demand on bus routes #17