TTC and Service Metrics

I await the new service metrics with near baited breath.

I will say however, that there are a couple of issues that I think need to be directly addressed in the new metrics.

1-Headway measurements that are more meaningful. That is the number of minutes of excess gap on a line.  Service that is stacked on the previous vehicle, should  not count “as at or under headway” for a measure.  It should not be that 9 buses in 4 minutes and one bus 56 minutes later counts as 90% of service as at or under headway.

2-Actual vehicle loadings.  That bus that is at the end of a gap, and cannot be boarded, is not useful service.  This too needs to be accounted for.

3-Trip time: Actual trip times including potential wait times at stop.  Ideally we would permit some measure of trip time, that included both an average, and the outer bound exceptions.  If there was a large gap in service, that gap time would need to be included in the trip time calculation.  It does not only matter that it should take 60 minutes to get from Scarborough to Downtown, it also matters that I had to wait for 3 average service headways to board a bus to get to the subway, and that trip took 90 minutes from when I arrived at the bus stop.

Also I think any “averages” should be weighted by number of riders, not vehicles.  A bus route with a 5 minute headway, to the current standard is on time at 2 or 8 minutes.  Clearly many more riders will experience the 8 minute headway than the 2.  Also the 2 minute headway will very nearly be a waste of a trip, while the 8 will be overloaded.  Ideally both these conditions would be seen as poor performance. especially if the issue started at dispatch.  If these 2 buses were in sequence for instance the 2 minute headway first, holding it would have allowed both vehicles to be exactly on headway.

I think the TTC needs to start keeping dispatch numbers, and keep total count of service dispatched late, with total minutes of late dispatch counted, that way a vehicle dispatched 20 minutes late would carry 20 times the weight of one dispatched 1 minute late.  Headway, not schedule is what needs to be watched on any frequent route.  A bus on a five minute headway that is 5 minutes late, will not be material if every other bus is also 5 minutes late, but will be a huge deal if the rest of the line is running 5 minutes early.


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