Recently a lot of discussions have been occurring on how AT decides whether to place a Transit Lane vs a Bus Lane, I decided the investigate and this is what I found.

According to the AT Code of Practice on the matter, the following flowchart is used

So for a route to qualify for a Bus Lane it has to

1. Be either a Frequent Transit Network route or have 15bph.
2. Have a Level of Service lower than C

3. Then under a corridor productivity assessment be recommended as a Bus Lane which can be seen from the below example for Dominion Rd.

The productivity is calucated as follows:

Corridor productivity of the route is defined as the movement of people through a corridor by lane per hour. Corridor productivity is calculated by multiplying the number of person trips with travel speed, expressed as an average by lane for the corridor. As such, the higher the number of person trips accommodated by lane per hour, or the higher the corridor productivity, then the more efficiently the route is operating. Austroads have suggested a benchmark value of 38,000 person-km /hour per lane be used to reflect favourable corridor productivity or efficiency of a corridor. In practise, a corridor productivity of 75% of this benchmark or higher, is desirable on arterials. This Austroads value is derived from the productivity pertaining to a single lane carrying 900 vehicles/hour with an average travel speed of 35 km/h, which is representative of LOS B, and reflects a high level of productivity or efficiency for the route. Applying an average occupancy of 1.2 to 1.3 per vehicle, results in the 38,000 person-km/hour per lane value adopted in the assessment. By way of comparison, 20 buses travelling at the same average speed, with occupancies of 55 passengers per bus, surpasses this productivity benchmark, and demonstrates the significant potential buses have in exponentially increasing productivity along a corridor. Another way of describing this is to note that the efficiency of a bus lane with 20 well-occupied buses will always be greater than the alternative of allowing that lane to be filled with traffic. As an example, Dominion Road currently carries 34 buses in the morning peak hour. With the addition of a further 6 buses, the bus lane on Dominion Road will have the potential to operate at a productivity or efficiency, of double the 38,000 person-km/hour per lane benchmark. To achieve the same productivity without the bus lane, there would effectively need to be two additional general lanes added to the Dominion Road cross-section.

Taxis are also allowed to use Transit Lanes regardless of passenger or not:

Taxis are permitted to travel on T2 or T3 lanes, whether or not there are an appropriate number of people on board, on the basis of the vehicle being a passenger service vehicle. This however does not apply to bus lanes.

However, the big weakness, especially with Transit Lanes, is the non-compliance as they are much harder to enforce. If we are to stick with T3 lanes for major Bus Lanes we really need to get better on this.

Another weakness is also, for example, take Manukau Rd is extra congestion is caused by cars merging in/out of the Transit Lanes to try to overtake buses.

It would also be interesting to see a recent Corridor Productivity Assessment for Manukau & Onewa Rds

So what do you think of the AT Code of Practice standards on the issue?

1. By definition the routes of the 31, 32 and especially the 33 (Great South Road from Papakura to Otahuhu Station) should all have bus lanes operating 7-7 7-days a week. So where are those bus lanes Auckland Transport?

As I see it Bus Lane or general. Transit lanes unless enforced strictly just seem to be extremely inefficient in moving people.

1. 01anthony says:

Last time I made a suggestion to AT on this, they did respond with that apparently they are working on bus lanes on great south road (around the Takanini area) but it is proving difficult due the cycle lanes being on the road already.

1. Similar to what I go
AT would be best to get those cycle lanes off the road and onto the paths and for now make them shared paths until we get some dedicated cycle ways in there. Road is wide enough

1. 01anthony says:

Yep I’m thinking the same sort of thing, those cycle lanes are scary as hell to use – no wonder only the brave (very few numbers) use them.

2. AKLDUDE says:

Interesting post. Mostly good points.
Looks like T3 is generally a good option as it doesn’t impede buses but does offer better utilisation of that road space 9% vs 4% and 59% capacity vs 53%.
“Another weakness is also, for example, take Manukau Rd is extra congestion is caused by cars merging in/out of the Transit Lanes to try to overtake buses.”
If traffic is flowing then no problem as they can hop into it easily. If traffic is stop-start then there is no need for them to change lane as the bus will be moving again and it is unlikely they would have even passed it by then.

1. Harriet Gale says:

Traffic would all move much faster if people knew how to drive correctly but they don’t hence the issue with the merging.

1. Bigted says:

plus issues with drivers failing to understand roundabouts.

3. This is all very rational except for the obvious problem: it doesn’t seem to cater for dynamic change, it is all about the current condition. It looks very much like a programme that will mostly reinforce the status quo.

For example, with improved priority the bus service will typically attract more users, simply because the journey will be faster and more reliable. Often requiring more capacity on the route, leading to increased frequencies which further increases service quality, therefore attracting even more users, and so on. A virtuous circle.

The causative move here is the installation of priority lanes, BEFORE there was the qualifying volume on the route… so does this process above allow for the feedback of pre-emptively improving the bus route in order to improve the street’s productivity in the future? It doesn’t seem to to me….?

1. Harriet Gale says:

I agree that is the big weakness in this system doesn’t anticipate for dynamic change well.

The other issue is we know this goes out the window when Business Associations/Local Boards push back so not as technical as they make it out to be.

1. Nick says:

My thoughts exactly. I suspect in the majority of cases where we have a T2 or T3 lane it’s because of that, rather than any technical analysis

4. Kelvin says:

The productivity can be a catch 22 scenario.

For example if the exisiting lane is slow, the bus will be congested and demand of bus patronage will be low. So the productivity for bus will be low.

And then some ‘analyst’ look at the low productivity and decide no bus lane should be built.

5. Sailor Boy says:

I too would love to see how they figured out that Onewa Road still doesn’t qualify for an actual bus lane.

I totally agree. At the very least extend the operating hours.

6. Streetguy says:

You probably need to stand beside a T3 lane like Onewa Rd, or drive down it, to see how well it works. Cars generally don’t impede the buses, either finding the big gaps in the timetable, or just trailing behind the buses happily from stop to stop. It makes driving with friends to and from the city centre nearly as fast as catching the bus (drop them off there and drive on to where you can’t get by bus).

1. Sailor Boy says:

“Cars generally don’t impede the buses”

You obviously only ever drive down the road. Catch a bus and you’ll realise how ridiculous your statement is.

1. AKLDUDE says:

On Onewa road there really isn’t anywhere for a T3 car to impede a bus as they are both doing the same thing (the few of them that there are), also buses simply aren’t THAT frequent on the route. you obviously don’t know that road very well at all Sailor Boy. As Harriet’s diagrams show unless the road is a very high frequency route a T3 actually has no negative impact on buses but does improve the overall capacity of the road by 6%… an easy win that is far more acceptable to the public than a bus only lane.

1. Sailor Boy says:

I rode a bus down there every weekday for a year. Believe me the T3 cars impede the buses. Especially when there are so many that the bus can’t get through the traffic lights on a single phase, or when they try to merge back into the right lane to turn, or don’t let the bus or of the indented bays.

Plus I count over 25 buses an hour in peak direction just on the 973, 974, 951, and 958

1. kevin says:

I live 20 metres from Onewa Road and travel down it (by car as I need a car for my job) every day.
Firstly to say that there aren’t that many buses is ludicrous.Buses are definitely impeded by traffic in the T3 lane but they still enjoy a much faster journey than vehicles in the other lane e.g. I only travel down Onewa for one block and it can take 30 minutes to travel that block
So I would be a big fan of increased enforcement as it shits me no end to see so many cars with one driver illegally using the T3 and then pushing their way in when they spot the enforcement camera.
One other thing that is annoying is drivers queueing across intersections. Given I cant use T3 it would help if I could actually get into Onewa.
If I could I would use PT without hesitation – from the perspectives of cost and time it is the way better option

7. Sid says:

Looks to me that Great North Rd the whole way between New Lynn and town should be a candidate for priority measures – whether bus lane or T2/T3 – once new network is implemented 11 June. Of course this would also mean removing the remaining parking that’s crazily allowed on it, and considering how better footpaths and bike priority can be incorporated too (the bits near New Lynn are slated to be part of the future bike network).

1. Realist says:

Yes need some vision and BACKBONE. Absolutely ridiculous that it should take 50 minutes to travel from New Lynn to CBD by bus. Thats an average speed of about 10km/h!

8. SamL says:

I would be very interested if Auckland Transport plan to implement either a Bus Lane or a T3 Lane along Great North Road (through Avondale and Waterview) given this is such an area of congestion and the New Network says buses are supposed to go through there every six minutes after the network is implemented. I cannot see them keeping to this timetable after Waterview Tunnel opens given the traffic that is going to flood onto local streets.

1. Stranded on the North Shore says:

From the plans that I recall seeing, AT always mentioned bus lanes on that road. But from my observations, with over 90% of cars being single-occupant vehicles, T2 would work quite well there too – it would nicely join the T2 on the NW onramp. Either way T2 or T3 would give people alternative (carpooling) to cars and buses. Given than buses are not anywhere near as frequent here as they are on Onewa Rd for example.

1. Anthony says:

Bus lane on Gt Nth Rd Waterview that is supposed to be built as part as part of Waterview connection appears like it will stop well short of motorway interchange, as the footpath has recently been reinstated such that there is not room

9. Harrymc says:

At least it’s good to see that they measure people rather than vehicles. I suspect that this will come as a shock to Hosking who believes his vehicle is more important than a bus full of plebs.

10. Matthew W says:

I’d be interested to know what process AT has for implementing centre lane running transit and signal priority.

11. It is very concerning that the bus lane along new north road does not continue through the Kingsland town centre. That is a major bottle neck for bus through put. It should of course be extended even further, but the center is critical because there are both direct services and the buses turning from morningside on to new north start there.