Are our road authorities working hard enough for us?
One statement that seems to pop up more than any other in my conversations with Australia’s road authorities goes something like this:
“Parts of our 26-metre B-double network don’t meet all of the minimum geometric requirements for Level 2A classification under the PBS Network Classification Guidelines.”
This is usually followed by commentary about insufficient lane widths, shoulder widths and bridge widths, and the amount of funding that would be required for rectification, despite Level 2A classification being intended to correlate directly with existing 26-metre B-double access.
To my mind this can mean only one thing: that the Guidelines are gold-plated. Rather than reflect the road geometric standards already accepted across our network for conventional 26-metre B-doubles, the Guidelines call for a utopian standard. And by not offering any guidance to road managers on risk-based decision-making with respect to roads that fall slightly short of the utopian standard, road managers are reluctant to stick their necks out. Why would they? They have nothing to gain if it works, and everything to lose if it doesn’t.
Advantia advocates a risk-based approach to road access decision-making. A utopian standard is fine, provided it is labelled as such, and accompanied by less desirable but nonetheless acceptable alternatives.
- Desirable requirements set out the ideal (utopian) standard
- Acceptable requirements set out a lesser standard that is suitable with no risk-mitigation
- Risk-mitigated requirements set out an even lesser standard that is suitable only with risk-mitigation.
While there is currently no formal implementation of such an approach for PBS network classification, looking at how things are done in various jurisdictions reveals a broad spectrum of approaches. The Victorian approach is a good example of a road authority properly sweating its assets:
- Even though many of its major highways are not suitable for 85.5-tonne A-doubles due to bridge capacity limitations, it has pre-approved access for A-doubles on those highways up to the maximum mass allowed on any structures crossed. Those masses are published on the VicRoads website, with indications of expected timeframes for mass upgrades on each structure.
- The soon-to-be-released 36.5-metre network (akin to Level 3A) will include many intersections that are unsuitable for a worst-case Level 3 combination to turn at, due to swept path capacity. The network will allow 36.5-metre combinations to turn at these intersections provided their individual swept path width does not exceed the identified maximum allowed for the intersection.
If we wait for everything to be perfect before we take a step forward, we will never move.