camaro68 wrote:Question for the rocket scientist out there. With regards to the induced demand theory of everyone using the proposed N/S freeway, do you think that the amount of people using it will outweigh it's through put ability?
Will there be an inifinte number of cars to do that? Surely a 3-4 lane freeway in either direction would be able to cope with any possible induced demand.
A freeway's single biggest failing is that it does cannot exit in isolation. Congestion on a freeway is almost always caused by off-ramps, that is, the roads beyond the freeway. Driving though Sydney you see this a
lot, queues of traffic from arterial roads running back onto the freeway. You literally do get situations where a 6 lane motorway comes to a standstill because of a set of traffic lights several kilometers up the road.
Think about the car parks!
camaro68 wrote:I guess the flip side we can spent the money building a more effective public transport system, I'm sure CEVA logistics would love to tranport a few shipping containers on a bus.
If you can get people out of cars and onto trains and buses, the road system benefits! Adelaide's PT network is so sub-standard that even the smallest investment can pay big dividends for both networks.
According to Transport SA, at South Road's busiest section, just south of Adam St in Hindmarsh, there are an estimated 50,800 vehicles, two way traffic. Just 10% of this is estimated to be commercial traffic. On Adelaide's busiest and most important freight route, commercial vehicles account for just 1 in every 10 vehicles
at most. This falls down to just 5% around Flinders University. Marion Road records as low as 3.5% points, Goodwood Road just 2.5%.
http://www.transport.sa.gov.au/transpor ... olumes.asp
So the other 90% or more of traffic is private cars. The figures for car occupancy, depending which study you look at, vary around 1.1 to 1.4 persons per car. Let's be generous, and say it's 1.4. Now, a 4-car Adelaide train can carry about 400
seated passengers - that's 285 cars before anyone needs to stand. You can easily double that with standing passengers.
If Adelaide had the capacity to run a train like this every 15 minutes between 7am and 9am that's over 1,100 cars removed from the road with seated passengers only, and another 1,100 on the return trip. Already that's 5% of typical South Road traffic past Flinders Uni.
Even this is a rail setup that would be considered substandard in the four larger cities. Adelaide could run six or even eight car trains with a simple platform extension, and every 5 minutes is arguably achievable if we had the rollingstock. Our trains run less often and are the smallest in the nation. We have the lowest PT usage of the five major cities. Adelaide's limiting factor isn't the length of track or passenger demand, but the number of vehicles, just 98 trains and 11 trams! There's some very low hanging fruit to be gained from Public Transport.
But what about our favourite truth of economics, induced demand? It's a killer for freeways because it is hideously expensive to increase the capacity of a freeway once it's built, and the limiting factor is almost always the roads around it. Well the amazing thing is induced demand works to the advantage of public transport! If a bus runs every 30 minutes and is full, logically it'd be feasable to run a bus every 15 minutes and double capacity. Suddenly the service is twice as frequent and therefore twice as usable, and more passengers follow. This can carry on as long as the population allows.
A bus that comes every 5 minutes becomes a very popular alternative. Even in little Canberra, the intertown bus route boasts a bus every 5 minutes and is the only service here to do so. It is slower than driving as it takes a longer path and stops more often, and all the other 'indignities' of bus travel. Despite this it is still packed, and this is a city one third the size of Adelaide.
A literal example: Before the city extension was even built and before many of the new trams had arrived, the Glenelg Tram carried the same number of people as 10% of the cars on Anzac Highway at West Tce, about 5150 people per day. Just 4% of traffic on Anzac Hwy is commercial vehicles. The government has ordered trams to double the size of the fleet, so we can take at least another 10% of traffic off Anzac Highway.
The trick we need to achieve is to get people out of their cars and into PT. As they say, one bus = 50 cars. Run a bus and you can move 70 people
and reduce road traffic. We can help
both systems by investing in PT.
I'll end with a fun fact. Sydney's CityRail baosts that they move 50,000 people per
hour on their busiest lines. South Road's busiest section carries 50,000 vehicles per
day.
of this post will convince the masses how accurate they are), let’s just agree to disagree. In years to come when Adelaide is left behind due to its lack of vision with anything resembling progress, then we can pull out all the induced demand and even chaos theory math and try to model that scenario. :wank:
Although I'm sure within a few hours, someone will have tried to kill the humour of the whole situation by stating that we can transport these goods on a train 
) with the density of Sydney. I had a quick look on Wikipedia and Sydney's density is nearly twice as much as that of ours, quite significant when you consider that they have a little bit more than 4 times our population.