Doncaster Hill was to be the key destination of Melbourne’s east, “a place to be”, and a vibrant self contained urban village. Manningham wanted to transform the character of Williamsons/Tram and Doncaster Roads into tree lined, pedestrian and bicycle friendly boulevards but did not allow for the huge volumes of through traffic they carry today or the effect of a poorly designed local street network.
Our traffic problems really began from the 50’s, when we abandoned the densely interconnected street grids that enabled efficient traffic dispersion, where people could get around, then changed our street design to suit the automobile. Road networks now start from an arterial road, then down a main road, onto a collector Road, then into a local street and onto a driveway at the end of a Cul-De-Sac. “Dead ends in more ways then one”..Patrick Condon Seven Rules For Sustainable Communities . Manningham Council had recently commissioned
a review of parking and traffic management on Doncaster Hill. It indicated that with the number high rise developments being completed there would be corresponding capacity constraints in the road network with limited opportunities available to accommodate the projected growth in traffic volumes. Congested traffic conditions similar to inner Melbourne are now expected. Increased traffic volumes will result in increased travel times and slower vehicle speeds in and around Doncaster Hill. There will be reduced performance of the road based public transport system (Buses Only) within the local area with an increase in stop-start traffic flow, queuing and delays at key intersections and limited gap opportunities for vehicles entering the arterial road network from our local road network.
Rule 2. Design an interconnected street system. Fine-grain interconnected street networks ensure that all trips are as short as possible, disperse congestion, and are compatible with walking, biking, and transit. The grid is the most common form of interconnected street system. Most streetcar cities have this characteristic street pattern, which is generally different than the post-1950 suburban pattern. The higher density of intersections reduces trip distance and reduces use of the automobile. Interconnected streets provide many alternative routes if there is congestion. By contrast, in sprawl form traffic is funneled into a few highly loaded main intersections, with no alternative routes. These overloaded intersections become magnets for big box commercial development. Including turning lanes, these can become ten lanes wide, with 400% more traffic and 60% more pedestrian fatalities. Engineers tell you that there is absolutely no choice but to have these. And within the constraints of the problem, they are right. It’s a condition of having a not-interconnected system. A higher density of intersections reduces trip distance and reduces use of the automobile.
So what’s makes transit so efficient in Vancouver? by Jarrett Walker & Associates
- It’s a grid, …
- … with an ideal spacing between arterials, about 800-100m, and
- it’s big destinations (what planners call anchors) are at the edges, not in the middle.
Grid pattern of arterial streets covers almost all of Vancouver. Most of the time, parallel major streets are spaced about every 800-1000m apart, and since a comfortable walking distance is about half that, this spacing is perfect for efficient transit. But what’s really great about Vancouver from a transit perspective is the position of its major destinations. They’re positioned in a way that solves another transit planning problem: anchoring. If a transit line is operating through an area of uniform density, about 50% of its capacity goes to waste. That’s because the vehicle will leave the end of the line empty, fill only gradually with passengers, and reach its maximum load at the midpoint of the line. After that, more people get off than get on, and as you near the far end of the line, the vehicle is nearly empty again. If you plot the load of the vehicle against the position on the line, you get a bell curve: zero at the ends of the line, and at its maximum level right in the middle. If you scale your capacity to the maximum level, you end up with a lot of wasted capacity near the ends of the line, and no way to make use of that capacity.
Above excerpt from Jarrett Walker & Associate’s website