Does the driving direction have an impact on distances?

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Does the driving direction have an impact on distances?

Postby Bernd Welter » Mon Mar 11, 2019 10:22 am

Hi there,

every once in a while customers wonder about the difference of distances depending on the relations direction.
In other words:
  • Why is the distance(A:B) not always equal to distance(B:A)?
  • Why is a distance matrix not symmetric?
The core answer to these questions is simple but requires more details:
The geometry of the routes is not the same, e.g. other roads are used.
AB-notEqual-BA.PNG
Route from Stuttgart to Madrid and back.
In the region of Lyon the router takes different superregional tracks

Of course the next question is then "why does the router not use the same streets?"

And then it comes to speed values and optimization. Here's another example:
DIRDistancePeriodCOSTTrack
N to S2060707194101666WEST
N to S +1862097733102025EAST
S to N1842617786102031EAST
S to N +2046477370102765WEST

So sometimes adding waypoints creates better distances and worsens the period. If the route is focused on period the +ROUTE is not better then.

Best regards,
Bernd
Attachments
SüdNord.plus.PNG
South to North plus waypoint
SüdNord.PNG
South to North
NordSüd.plus.PNG
North to South plus additional waypoint
NordSüd.PNG
North to South without any additional waypoints
Bernd Welter
Manager Technical Consulting & Requirement Engineering
Senior Technical Consultant Developer Components
PTV GROUP - Germany

Bernd at Youtube
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Bernd Welter
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Re: Does the driving direction have an impact on distances?

Postby Bernd Welter » Mon Mar 11, 2019 11:47 am

"Frankfurt Abflugbogen" (Frankfurt Airport: Departure) to "Frankfurt Ankunftbogen" (Frankfurt Airpoirt, Arrivals)

Absolute difference is not that big but from a relative perspective it is enormous:
1.200m versus 86m ;-)
Attachments
AB-notEqual-BA.PNG
Bernd Welter
Manager Technical Consulting & Requirement Engineering
Senior Technical Consultant Developer Components
PTV GROUP - Germany

Bernd at Youtube
User avatar
Bernd Welter
Site Admin
 
Posts: 1275
Joined: Mon Apr 14, 2014 10:28 am


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