The efficiency of buses?

Grail said :

A full bus carries 47 people.

~45 seated (53 on a steer tag), and during peak hour another 30+ standing.

A full bus carries 47 people. Thus to break even with people driving small cars, you’d have to drive 1km full to balance out every 10km empty.

We still need some actual figures from ACTION, but 1:10 assuming only full busses versus only empty busses is going to be fairly trivial. ACTION do not run empty busses every 5 minutes, but they do run full busses every 5 minutes. Thus every 5 minute run during peak times is worth an hour of night runs.

And of course for everyone who leaves the car at home and gets on a bus to get to work, the odds are weighted further in ACTION’s favour.

I expect that the ACTION bus fleet is working at parity with, if not significantly better than, the equivalent fuel efficiency of 1.0L engine cars.

There are lots of factors to consider. The ‘multiple trips’ issue is a big one for many, which includes things like dropping kids at school, and having to attend more than one place of work.

That said, public transport has huge potential. If I lived in a suburb that had good bus coverage (eg along an intertown route or walking distance to an interchange), our family would probably only own one vehicle rather than two. As it stands, buses to where I live are practically unusable, so two cars it is.

The intertown buses are only full because they take passengers from the (sometimes) not very full suburban routes. Thus a fair comparison will need to be made across the system as a whole, not just an individual route. Plus, of course, the infrastructure savings from having less cars on the road.

Finally! Common sense! I’m with you Deref; though I think there’ll be very few to echo your thoughts.

I think one of the most difficult factors to measure is the need for a very large proportion of the workforce to be mobile during the day. Most arguments assume commuters go from home to an office in the morning and from that office to their home in the evening. Most of the people I work with, though, move around the city during the day as well, and I can’t see any way public transport could cater for their needs. I for one don’t have a typical day in terms of where I need to be, and for my professional life I attend meetings anywhere from Bonner to the Naas Valley and sometimes as far as Batemans Bay. And my personal transport needs are similar. I don’t see how public transport could ever meet them. I’d like to see empirical data on what proportion of our workforce stay in one part of the city their whole day.

I’ve long thought a better and more sustainable response to environmental concerns is to put all our energy into reducing emissions from private transport, preferably with a view to eliminating emissions altogether without sacrificing the benefits of total individual mobility of private vehicles. And that’s not only a question of technology; how do you extend use of private vehicles to the poor, disabled and elderly to prevent social exclusion?

So like you I wouldn’t say I’m opposed to public transport, but this blind faith in its ability to save us all from complete annihilation reminds me of our dear friend Danny Nahlia…

I’ve had a bit of a look into this sort of thing in the past. IIRC the fuel efficiency of a big diesel bus is about 30-35L/100km. So you need 3-4 people sitting in a bus before efficiency per passenger kilometre is on par with a typical car (Also seem to remember reading that the average efficiency for passenger cars in Australia is about 10-11L/100km and the average occupancy 1.2 people per vehicle). As for time spent idling, my car uses about 1-2 litres an hour idling and uses about 3x less fuel per 100km than a bus, so I’d guess a bus would use probably 3-6 litres per hour idling.

Certainly the high frequency intertown routes with lots of passengers are dramatically more efficient than having the same number of people in cars, the infrequent suburban routes are potentially less efficient than cars given their indirect nature and low numbers of passengers. In addition to saving fuel, an intertown bus running at peak times filled to capacity takes about 80 cars off the road and out of office car parks.

The thing with a lot of the ACTION bus network is that it is largely designed as a social service to provide transport to people too old/young/disabled/poor to drive, so efficiency for many routes is probably not a priority.