A Renewed Case For Full Width Concrete Paving For High Speed, High Volume Roads : James Walker

A renewed case for full width concrete paving for high speed - high volume roads

James Walker1,

1 Project Development Manager, Bachelor Engineering (Civil), Transport for NSW

ABSTRACT

A typical modern NSW Motorway or Highway is 10.5m wide, consisting of 2.5m nearside shoulder, 2x3.5m travel lanes and an offside shoulder of 1m.

For many of these high speed - high volume - high heavy vehicle usage corridors, rigid pavements are the workhorse that provide durable, low maintenance, longer lasting roads.

Current construction practices and TfNSW standard drawings would see the paving of approximately 8.1m first pass (consisting of travel lanes and offside shoulder) utilising multi lane paver and tipper trucks. Following the first pass gaining strength, the shoulder would be paved with smaller paver and concrete delivered with agitators.

Proposals to construct the pavement as a single pass have been raised by many over the years.

With state road and transport agencies seeking to improve road safety outcomes for all, there has been ongoing calls for increased nearside shoulders to ensure they can function as a breakdown lane, with cars and trucks able to pull over clear of the travel lanes. Some have called for shoulders on our highest speed - highest volume roads up to 4m. This would result in a cross section up to 12m.

While this represents a huge improvement for road safety, it also raises the need to reconsider the case for full width concrete paving. Particularly when one considers potential benefits:

• Safety during paving operations

• Potential paving program efficiencies

• Reduced mix designs

• Potential cost savings

• Opportunities for long term network planning, considering usage of hard shoulders during peak times under smart motorway conditions