Is your feature request related to a problem? Please describe.
Currently the vehicle state unknown is considered 'Maybe PROW' in MDS (see State Machine Diagram). This has caused confusion among cities and providers as to when and why to include 'unknown' in PROW counts.
Note: how to use and implement vehicle state unknown by providers will be addressed in a separate issue.
Describe the solution you'd like
Provide guidance as to how to think about vehicle state unknown with regards to PROW counts based on MDS data.
Is this a breaking change
Imagining this would mostly be updates to descriptions but could change how the spec is being implemented depending on the outcome of the conversation.
I'm not sure
Impacted Spec
This will affect all of them.
agency
policy
provider
Describe alternatives you've considered
Leave things as is?
Additional context
Discussion Point A - unknown is NOT PROW
It really can't be overstated how natural "sum up the PROW states to count PROW" is. If we can standardize how long can a vehicle go without an event before moving to unknown via missing", and we then decide that we have enough standardization, so we stop counting unknown as PROW.
You might worry that providers would abuse this ability to move things to unknown if that is all it takes to remove things from PROW. But cities can still track unknown for other purposes, for example cities could use "% of fleet in unknown state" as a measure of operational quality.
I've seen instances where vehicles have a lot of transitions into and out of unknown on relatively short time scales via the comms event types and I would think those should continue to count as in the PROW. Whether a vehicle state is considered in or out of the PROW matters a lot for something like determining how long a vehicle has been parked in one place, which is a common regulation we help enforce at Populus. A vehicle that enters unknown on lost_comms and then goes back to available on comms_restored some time later in the same place has clearly not moved and we would consider that a continuous in-PROW parking event. But an unknown/missing transition would terminate the parking event under this model where it's used to communicate that a vehicle is permanently lost.
Discussion Point C - split unknown into missing and out-of-communication states?
For MDS 2.0 we could "split" unknown into missing and out_of_communication (or some such thing) if we want to make the distinction clear at the state level rather than the state/transition level.
Is your feature request related to a problem? Please describe.
Currently the vehicle state
unknown
is considered 'Maybe PROW' in MDS (see State Machine Diagram). This has caused confusion among cities and providers as to when and why to include 'unknown' in PROW counts.Note: how to use and implement vehicle state
unknown
by providers will be addressed in a separate issue.Describe the solution you'd like
Provide guidance as to how to think about vehicle state
unknown
with regards to PROW counts based on MDS data.Is this a breaking change
Imagining this would mostly be updates to descriptions but could change how the spec is being implemented depending on the outcome of the conversation.
Impacted Spec
This will affect all of them.
agency
policy
provider
Describe alternatives you've considered
Leave things as is?
Additional context
Discussion Point A -
unknown
is NOT PROWIt really can't be overstated how natural "sum up the PROW states to count PROW" is. If we can standardize how long can a vehicle go without an event before moving to
unknown
viamissing
", and we then decide that we have enough standardization, so we stop counting unknown as PROW.You might worry that providers would abuse this ability to move things to
unknown
if that is all it takes to remove things from PROW. But cities can still trackunknown
for other purposes, for example cities could use "% of fleet inunknown
state" as a measure of operational quality.Note: more context in https://github.com/openmobilityfoundation/mobility-data-specification/issues/749#issuecomment-1136539318
Discussion Point B -
lost_comms
vsmissing
I've seen instances where vehicles have a lot of transitions into and out of
unknown
on relatively short time scales via the comms event types and I would think those should continue to count as in the PROW. Whether a vehicle state is considered in or out of the PROW matters a lot for something like determining how long a vehicle has been parked in one place, which is a common regulation we help enforce at Populus. A vehicle that entersunknown
onlost_comms
and then goes back toavailable
oncomms_restored
some time later in the same place has clearly not moved and we would consider that a continuous in-PROW parking event. But anunknown
/missing
transition would terminate the parking event under this model where it's used to communicate that a vehicle is permanently lost.Note: more context in https://github.com/openmobilityfoundation/mobility-data-specification/issues/749#issuecomment-1137657499
Discussion Point C - split
unknown
intomissing
andout-of-communication states
?For MDS 2.0 we could "split"
unknown
intomissing
andout_of_communication
(or some such thing) if we want to make the distinction clear at the state level rather than the state/transition level.Note: more context in https://github.com/openmobilityfoundation/mobility-data-specification/issues/749#issuecomment-1137583731