Dynamic speed limits

[rac]

Hi,

Can you advise whether the speed limits available do (or can) take into account variables such as the time of day, weather conditions, vehicle type

- vehicle type (e.g. passenger vehicles are 60kmh but trucks are 40kmh in the same stretch of road at all times)
- weather based (e.g. in dry conditions the speed limit for all vehicles is 100kmh, but is reduced to 90kmh if the road is wet)
- time of day (e.g. within school zone times of Monday to Friday 14:30 to 16:00 excluding school holidays)

This would be for both European & Australian based roads

Cheers

k

[Joost]

To answer your questions:

- vehicle type
By default only Car. For the GB we have extra data available with speed limits for trucks. Contact your sales representative fore more details. For the rest of Europe it is not needed since truck limits are generally the car limits with a max of 80 kmph.

- weather based
This is available in the data

- time of day
Partially. We have available in our model if their is a time dependent speed limit , but not the actual times the limits apply to. Coverage time dependent data may vary. On thee major road networks the coverage is good, outside of the major road network the coverage varies. We do not have statics on how good the time dependent data is covered.

[Bernd Welter]

And here's just a screenshot taken via a testclient.
I performed a routing based on Europe City 2017.1H map and activated the SpeedInfos.

Structure of speed limits

[rac]

Hi Both,

Many thanks for your (as usual) very quick response!

A few quick follow-ups if I may

1) Do you have data for the examples (vehicle type/weather/time of day) for Australia also?

2) I'm not sure I fully understood the answer to 'time of day'

a) Are you saying you have time dependent speed limit values in the database or simply a flag indicating there is a time dependent limit but not what it is.
b) And that there is no data related to the times that limit applies?[/list]

Many thanks

k

[rac]

Hi,

As an example of the issue with regards to variable speed limits I am attaching a picture of a road in Sydney that we are receiving an indication that the speed limit is 40kph - the 2 red circles show where the variable speed limit applies

In reality this road has a speed limit of 70 kph except during school times (non school holidays Monday to Friday, 8-9:30am and 2:30pm to 4:00pm)

For road segments where there is a variable speed limit will both the variable & normal limit be returned & if so which one will be returned as the 'first' or default choice?

Kind Regards

k

[Bernd Welter]

here is a screenshot demonstrating what is available over there...
Important: depends on the exact usecase - you shouldn't mix up historical speed values with limits.

Historical speed values based on PTV_SpeedPatterns.
The histograms show the driving time and period for each route from january 1st-january 8th, 00:00, 01:00, ..22:00, 23:00....

sample route with xRoute output

@Joost: you know the usecase - maybe you can add some comments...

[Joost]

The speed limit data in our binary maps does not have all the properties we have available in our source data. Therefor you do not see a difference between the regular limit and the time dependent limit.

However: in your case I know that you have the source data licensed (spl and ls2 files). In the source data you can see witch limit is the time dependent limit by looking at the LIMITTIMECONDITION attribuut of a speed limit.

The data however stil does not show you the actual times for it. You could us historic traffic data to make estimates (Bernd example) but I would not rely on it.

PS For Australia we have a similar setup for truck limits as we have for the UK. Not available in our standard but is available on special request.

[rac]

Hi,

Just to come back on the time of day speed limits

You indicate you have available in your model if there is a time dependent speed limit, but not the actual times the limits apply to.

Can you advise on the reason for the inclusion of a time-dependent limit in the data? For example are all time-dependent limits in the data for Australia for schools or are there other reasons for a time-dependent limit at a particular location.

Would it also be possible to provide some more information on the potential inclusion of applicable times in the data later in the year

Your early response would be much appreciated

[Joost]

Would it also be possible to provide some more information on the potential inclusion of applicable times in the data later in the year

I just received word that the validity times of speed limits are now available for Europe. Australia is still under consideration. I would recommend to stay in contact with your sales contact. He's aware of your request and working on it.

Can you advise on the reason for the inclusion of a time-dependent limit in the data? For example are all time-dependent limits in the data for Australia for schools or are there other reasons for a time-dependent limit at a particular location.

The current dataset for Australia does not always specify a specific circumstance for time dependent speed limits. But since they also include time dependent limits of 80 kmph I would assume that these are not part of schoolzone. Unfortunately I can not reverse search from a limit to a location to check the specific circumstances.

Overall: it is not uncommon that time dependent speed limit do not specify a reason. I would argue that more often they do not specify a reason then they do in reality and thus also not in our data.

[rac]

Thanks for the quick reply Joost; one final clarification if I may?

You mention a couple of times in your response that it is not uncommon that time dependent speed limits do not specify a reason. I am not familiar with where the 'reason' is specified, what are typical values of this reason?

Kind Regards

k