Talk:Australian Road Types & Naming: Difference between revisions View history

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* This suggests that, in an area of inadequate mobile coverage, the road type could initially be set to a type which has a default average speed appropriate for the road, and then changed AFTER the tile update to be the right type according to the normal rules.
* This suggests that, in an area of inadequate mobile coverage, the road type could initially be set to a type which has a default average speed appropriate for the road, and then changed AFTER the tile update to be the right type according to the normal rules.
* Not yet determined whether the speed limit set at the time of segment creation has an effect on default avergage speed.
* Not yet determined whether the speed limit set at the time of segment creation has an effect on default avergage speed.
* Also undetermined whether "unpaved" flag affects default speed.

Revision as of 02:06, 13 January 2019

Notes on default speeds for various road types

(This is an evolving record of my understanding of default speeds. It contains conjecture, but may evolve into something that can become part of the main Wiki article.)

  • Waze sets a default average speed for road segments when they are first generated. When drivers use the road with Waze running, Waze updates the average speed based on the speeds it sees
  • Waze probably records the elapsed time to traverse each segment and make each turn at the end, although we usually refer to it as recording the speed rather than the time. One implication is that it only needs to know the time at the start and end of the segment; loss of GPS coverage in the middle (as in a tunnel, for example) shouldn't matter.
  • If Waze doesn't have a server connection at the (?beginning and?) end of the segment, it won't be able to update its record of the elapsed time for the segment. (Subject to whatever buffering of data it does when it doesn't have a connection to the server - which appears to be minimal.) This means the average speed for the segment may never get updated.
  • This presents problems in remote areas with no mobile coverage. Segments may have unrealistically low average speeds, resulting in much higher estimates of travel times, and sometimes selection of a longer route which in reality is slower.
  • The default speeds for the various road types, based on the Route Speeds script, are:
Segment Type Default km/hr Comment
Narrow Street 20 May not represent actual implementation
Private Road 20
Street 20
Primary Street 30
Ramp 65 May depend on type of connecting roads
Minor Highway 65
Major Highway 75
Freeway 100

Some of these are unrealistically low - a country Minor Highway is likely to have an average speed well in excess of 65 kn/hr. For example https://www.waze.com/editor/?env=row&lon=114.69867&lat=-28.62531&zoom=2&segments=264477048 is a Minor Highway but has an average speed of 100 km/hr.

  • The default average speed seems to be set at the time the new segment is processed by a tile update, not when it is saved.
  • This suggests that, in an area of inadequate mobile coverage, the road type could initially be set to a type which has a default average speed appropriate for the road, and then changed AFTER the tile update to be the right type according to the normal rules.
  • Not yet determined whether the speed limit set at the time of segment creation has an effect on default avergage speed.
  • Also undetermined whether "unpaved" flag affects default speed.