Road flaring, what is it and why it sucks in a urban environment

Road flaring is the gradual corner radius that occur at all intersections, it allows traffic to flow smoothy around corners rather than making sharp 90 degree turns. An extreme example of road flaring is a freeway interchange with long flowing corners and high vehicle speeds, the tight 90 degree bends in carparks are at the opposite end of the scale – you see more common examples on your own street

Freeway Interchange

So why is road flaring, particularly excessive road flaring, a bad thing? In Australia, and most countries I am aware of, cars are required to give way to pedestrians crossing a side street they are turning into. Sounds great in practice but several things stop that happening

1. It is one of the road rules that most drivers seem to conveniently forget/ignore
2. Excessive road flaring increases the vehicles turning speed, making crossing more dangerous for pedestrians
3. Excessive road flaring also increases the length of the crossing for pedestrians. This “exposure time” is the dangerous time a person must spend dashing between kerbs

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This road rule also comes in as the number two most misunderstood road rule

This lack of understanding is made worse by the use of excessive road flaring in our urban environment. A lot of intersections are simply over designed allowing drivers to take corners at a high speed with barely a touch on the brake pedal and they aren’t looking to give way to any pedestrians crossing in their path. It is not uncommon to see pedestrians either wave drivers through, or simply standing stranded at a corner waiting for a break in traffic before crossing – despite having right of way.

So how to fix this? Firstly, what do the standards say? The Austroads Guide to Road Design Part 4: Intersections and Crossings, requires different levels of road flaring depending on the road type and intended design vehicle. The guide sets out what size design vehicle is required to be able to safely and legally make the turn – larger vehicles may still access the street, but may encroach on the other side of the road as this is deemed to be a very infrequent event. The guide recognises that “it is good practice to provide the shortest crossing of the road that is practical” – seems simple enough.

Below is a particularly terrible example in Brisbane, the intersection of Aberleigh Rd and Butterfield St.

The building on the South-East corner is a child care centre and is busy with parents dropping off their young children. Unfortunately the crossing distance is approximately 35 metres – how would you feel crossing this street with your child? The crossing has been split with a pedestrian refuge, but the crossing lengths between are huge and vehicle approach speeds are excessive.

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If we ignore the bus stop on Butterfield St as it complicates the intersection design slightly, and redesign the intersection in accordance with the standards, look at how much smaller this intersection could be. Crossing distances are greatly reduced, vehicle speeds are slower, and the reclaimed space can provide green landscaping and seating for people to enjoy.

Are there any streets near you suffering from excessive road flaring? What is it like simply crossing the street? Let me know.


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