Turn restrictions |
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There are 2 types of restricted turns:
•Banned turns •Delayed turns
Normally you will be using banned turns only, since for most normal routing purposes, setting different road speeds for road classes are sufficient for giving a realistic route choice.
Generally you can change choice of route A LOT by using wrong values for delays, so take care.
If you add a turn restriction, where one of the links making up the restriction is already marked as one-way, it is skipped. You will not notice this unless you export the turns.
Fileformat
Turn restrictions are stored in a text file, space-delimited.
The format is one or more lines, where each line stores one restriction with parameters.
7 different types of restrictions are possible:
0: Simple Turn restriction, 2 external link ID's + 1 cost value 1: Simple Turn restriction, 2 link ID's + 1 cost value 2: Turn Standard, coordinates for node (rarely used, see RW Net 4 documentation for details) 3: Mandatory turn, 2 external link ID's 4: Mandatory turn, 2 link ID's 5: Complex Turn restriction, >2 external link ID's + 1 cost value 6: Complex Turn restriction, >2 link ID's + 1 cost value
Example:
// Comment 0 A4003234 A4003127 -1 1 456 230 -1 2 -77.024098 38.902711 3 A4003234 A4003127 4 456 230 5 A4003279 A4003234 A4003127 -1 6 89 456 230 -1
Lines starting with // are ignored as comments.
If you use turn restrictions with external ID's (type 0, 3 and 5), make sure you have opened the network with an external ID.
Type 0, 2, 3 and 4 gets translated into one or more type 1 during import and type 5 gets translated into type 6 during import.
If you export the turn restrictions, you will only get type 1 and 6.
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