Travel speeds per mode

(outline, to be written out)

Link impedance is normally length divided by an assigned speed. How that speed is assigned is one of the least visible and most consequential modelling choices: it decides whether a motorway detour beats a direct local road, and therefore which routes the model believes people take.

Planned contents

• Speed by road type: the lookup table approach, and the average travel speeds per OSM road type determined with the Department of Spatial Economics, VU Amsterdam
• Free flow versus realised speed: why the posted speed limit is the wrong number, and how TomTom style speed profiles by time of day are used in the Dutch national network model
• Correcting implausible source values: speed limits in OSM that are absent, mistyped or physically impossible
• Cycling: the effect of surface, elevation and wind, and why a single average cycling speed is a poor approximation over long distances
• Walking: typical speeds by age and mobility, and why this matters for social domain applications
• Junction and crossing costs: the time lost at intersections, which dominates in dense urban networks and is invisible in a pure length over speed model
• Access, egress and parking time: the part of a car trip that is not driving

Related

• Travel impedance · Building a routable network · Network data sources