Just under a month ago I blogged about the spreading T2 lane disease, and the fact that North Shore City Council were considering destroying the highly successful Onewa Road transit lane by allowing vehicles with two occupants, rather than just buses and vehicles with three occupants, down the transit lane. After that Council meeting it seems as though the bewildered officials went away to do a bit more work that would hopefully show the Council what an absolutely stupid idea the change would be. The result of their further work can be read in the agenda item to the upcoming July 13 meeting of the Infrastructure and Environment Committee (relevant pages here). Further information on Onewa Road is being collected for presentation at the August meeting, but my reading of the information added in shows that messing with Onewa Road would be an absolute disaster.

A brief history of the T3 lane, and a description of the current situation has been outlined: There are a number of interesting things here. Firstly, it is pretty amazing to hear that the transit lane has been in operation since 1982! That’s long before there were any bus lanes in Auckland from what I know. It’s also interesting to note that between 1982 and now there are around 300 fewer vehicles travelling down Onewa Road during the morning peak, but that those 300 fewer vehicles are carrying 700 more people – thanks to the incentive that the transit lane provides.

The council officers then undertook an analysis to determine what the effects of changing the lane from T3 to T2 would be. These were the results: Two things here stand out for me. The first is how wonderfully effective the current situation is: with the transit lane carrying around 80% of people during the 7.20-8.20am hour, which is the busiest. The second thing is the absurdity that would happen if we changed to a T2 lane where there would be more vehicles using the transit lane than the main lane – completely negating the entire purpose of it!

The report’s conclusions are pretty unequivocal: Of course councillors are known for their ability to make completely illogical decisions, so I guess we’ll wait and see exactly what happens here. What is interesting is the final sentence, which indicates that there might actually be a case for increasing the threshold for people to use the transit lane – because the number of vehicles in that lane is starting to push the limit of efficiency for that lane. Conversion to T4 or even to a bus only lane might actually be needed at some point in the future. This is further reinforced by a historical analysis: In my opinion Dominion Road is likely to be somewhat similar to Onewa Road, in that both currently experience severe congestion, both have a large number of buses along them and for both a T2 lane would be completely stupid. As Onewa Road’s pushing the limit for even a T3 lane working without disrupting buses, I have strong doubts that a T3 would be the most suitable solution for Dominion Road.

I’ll keep an eye out for the decision on this. Also, kudos to ARTA to writing to the council and telling them what a dumb idea the change would be – please do something similar for Dominion Road!

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  1. And the numbers above are only based on current observed traffic. Once the second order effects of changing incentives is realised, there would be no value in the transit lane at all, and likely every single vehicle would be worse off.

  2. That’s quite an impressive rise in the number of bus services being provided in the last 30 years (given that the population served can’t have expanded that much). It’s almost like have T3 lanes makes taking the bus more attractive… 🙂

  3. Most of that rise has been in the last 7 years, interesting to see it dropped from 32 in 1982 to 24 in 1997 (along with a halving of passenger numbers) and up to 66 in 2010 (during which passenger numbers trippled c.f. 1997).

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