What’s all this talk about a P-turn in Melbourne?

Hoddle street traffic at night

This week there’s been mentions of  P-turns in Melbourne, arising from the State Government’s proposed changes to the intersections at:

  • Hoddle Street, Swan Street and Olympic Boulevard, Melbourne
  • Hoddle Street and Johnston St, Collingwood.

This post explains a P-turn, and whether we think it is right for Hoddle Street.

Why a ‘P-turn’?

The term itself is of US origin. It makes sense if you drive on the right-hand  side of the road. But we don’t and it’s confusing.  It certainly doesn’t look like a ‘P’ when you drive on the left side of the road. We’ve been calling it the ‘remote right turn’ because it better describes what a driver has to do.

The best known remote right turn is the one on Moorooduc Highway in Frankston, for northbound traffic to do a right turn into Cranbourne Road to head east. To complete the remote right turn, drivers turn left on to Cranbourne Road, then complete a U-turn via a signalised U-turn intersection to then head east on Cranbourne Road. This temporary fix was installed to address congestion issues at the end of the Frankston Freeway, prior to Peninsula Link, but VicRoads has since announced that it is permanent.

Illustration of a P-turn

What are the benefits?

The benefit of a remote right turn is that it removes the need to provide a green light for right turning traffic at an intersection.  It means that the time that would otherwise have been used for the right turn can instead be used for through traffic.  More ‘green time’ is provided for the major flow of through traffic.

It can also reduce the width of intersections by eliminating turn lanes, reducing the width of the road to be crossed by pedestrians. This isn’t the case at Frankston.

What are the problems?

The problems with the remote right turns are that they can be confusing to new or infrequent users of the intersection. The idea that to turn right you need to go past the location and complete a U-turn, as proposed for Hoddle Street and Johnston Street, or to turn left and make a U-turn like on Moorooduc Highway or proposed for Hoddle Street and Swan Street, could be confusing. On congested roads, a driver may be in the right lane to turn right then find that they need to instead be in the left lane to turn left! They also require turning vehicles to travel a much greater distance, and require more stops. This is offset by better flow for traffic in other directions.

What’s different about Hoddle Street, Swan Street and Olympic Boulevard?

The State Government’s proposal for this intersection combines the remote right turn (P-turn) for northbound traffic on Hoddle Street with an element of the continuous flow intersection for southbound traffic on Hoddle Street. We’ll write about continuous flow intersections in another post.

Will the P-turn help fix the problems on Hoddle Street?

The proposed intersections works, combined with permanent Clearways on Punt Road, will provide some short term relief, and should be trialled as we’ve written about before. However much more is needed, including removing on-street parking along Hoddle Street so that a complete northbound bus lane can be provided.  Medium to long-term planning should be for underpasses of key intersections or a tunnel from the Eastern Freeway to Swan Street, widening Punt Road to three lanes in each direction south of the Yarra River, and separated bicycle lanes.

Have your say

You can have your say on the proposals for Hoddle Street via the VicRoads engagement website, before 11th September 2016.

Main image source: https://www.flickr.com/photos/avlxyz/License CC BY-NC 2.0.

Written by Dave Jones, Roads and Traffic Manager
August 19, 2016