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The attribute for each link in the network play a key role in defining how the link is used in the routing calculations. This is defined through a bit-pattern:
1. Road class, 0-31 (5 bits) These have no predefined meaning, but their value can be translated into a drive time using function CalculateTime
2. Hierarchy (*), 1-5, (3 bits, 32-64-128, bit 5-7) A topological hierarchy can be used for speeding up TRouteCalc calculations. 0 is also allowed, if you don't use the hierarchy at all. See further explanation here: Hierarchy.
3. No-drive through (*), true/false (1 bit, 256, bit 8) This can be used to define areas, where you are not allowed to drive through to get to the target. Applies to TRouteCalc calculations. See TNetwork.NoDriveThroughCheck, TNetwork.NoDriveThroughInit and TRouteCalc.NoDriveThrough
4. One-way, To-From direction not allowed, (1 bit, 512, bit 9)
5. One-way, From-To direction not allowed, (1 bit, 1024, bit 10)
If both bit 9 and 10 are set, the link is closed for driving.
6. Roundabout, true/false (1 bit, 2048, bit 11) Can be used in creating driving directions.
7. Non-driving link, such as a ferry or car-train, true/false (1 bit, 4096, bit 12) Can be used in creating driving directions.
8. True if not allowed to make U-turns at the From-end of the link. (1 bit, 8192, bit 13)
9. True if not allowed to make U-turns at the To-end of the link. (1 bit, 16384, bit 14)
10. SkipInSearch (*), true/false (1 bit, 32768, bit 15) For use with function NearestLocation See SkipLinks2BitArray and TSpatialSearch.SkipLinks
(*): Changed from RW Net 2.
An example:
A road of class 4, which can only be travelled in the direction of digitization: 4 + 512 = 516.
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