Unidirectional traffic signal segments are currently not compressed.
This means traffic signals which are not on turns can be missed and
not applied the correct penalty.
This commit changes this behaviour to correctly handle the graph
compression. Additional tests are added to ensure there is no
regression for other cases (turns, restrictions).
Co-authored-by: Michael Bell <michael@mjjbell.com>
Weight and duration penalties are flipped in the lambda function
that applies penalties from traffic signals.
Duration is in deciseconds, whilst weight is multipled by
10^weight_precision, with weight_precision being 1 by default.
Therefore, for default routability profile, the penalties end up
being the same, hence why no tests picked this up.
If distance weight is used however, it will incorrectly apply an
additional penalty to the weight, and not add the traffic signal
delay to the duration in the routing graph.
To confuse things further, in some API responses the values are
correct because they use geometry data instead, but it's still
possible that a sub-optimal route was selected.
However, given the distance weight is in meters, and the additional
penalty per traffic light would be 20, it's unlikely this would
have changed the routing results.
In any case, we correct the function to apply the arguments correctly.
Currently OSRM parses traffic signal nodes without consideration
for the direction in which the signal applies. This can lead
to duplicated routing penalties, especially when a forward and backward
signal are in close proximity on a way.
This commit adds support for directed signals to the extraction and
graph creation. Signal penalties are only applied in the direction
specified by the OSM tag.
We add the assignment of traffic directions to the lua scripts,
maintaining backwards compatibility with the existing boolean
traffic states.
As part of the changes to the internal structures used for tracking
traffic signals during extraction, we stop serialising/deserialising
signals to the `.osrm` file. The traffic signals are only used by
`osrm-extract` so whilst this is a data format change, it will not
break any existing user processes.
