Search with Line Parameters
The desired lines make no distinction in direction since there are very few solutions that would satisfy a request, which contains both directions of the particular line.
If the parameter is generally used to force the system to use the backbone (for example, subway), the direction cannot be specified ahead of time for an unknown request. However, for fine-tuning a specific search, marking an unwanted direction of the required line as suppressed would force only the wanted direction to be used.
Since the required lines also count as desired, a solution that includes all required lines and none of the lines that are explicitly marked as desired is still considered to be valid.
Apart from fine-tuning a particular search, the Lines parameter is particularly convenient to be used on a regular basis. See the example in the following graphic:
- Perform Step 1 as mandatory, looking for the direct itineraries or ones with one transfer only (this search should be quick).
- Perform Step 2 as mandatory, looking for itineraries with two transfers that include line 099 (this search should be quick).
- Perform Step 3 only if the previous steps produce no results, looking for all itineraries with two transfers (this search could take a long time).
- Perform Step 4 only if the previous steps produce no results, looking for the
itineraries with three transfers (this search could take a very long time).Note:
In steps, the step parameter takes precedence over the general parameter of the same type. For Lines, however, the two are combined. This is done so that modifying a particular search when Lines are used in steps does not require you to retype the desired line in all steps.