Holdfast Training Services Trial Blog

The Calder Highways Overtaking Lanes (CHOTLs) project is to construct 2 overtaking lanes on a stretch of very straight, sleep-inducing, 2 lane – 2 way road some 550kms from Melbourne in rural Victoria.

As Design Manager for the CHOTLs, I held a kick-off meeting with the Client (a local highways authority) to nail down what was in my scope of works and what was out.  I then drove the 6 hours to the proposed locations to do a site walkover (lessons learned from the Amaroo project).

I am to deliver a detailed design to the Client by the end of June.  Drainage and pavement structural design are not included in the scope of works.  The OTLs are to tie into and match the existing pavement structure with subsurface drainage excluded from design.  Essentially, I am delivering the geometric design.

So, Q1; “what is the enemy doing and why”?    Remembering the triple bottom line (people, profit and planet), my enemy is the planet, and it does what mother nature says it must.

The stretch of road where the OTLs will be constructed is extremely environmentally sensitive.  Buloke trees and the mallee emu wren make planning construction in this area a challenge and has already resulted in a re-visit to site to seek alternative OTL locations.

Mallee-emu-wren

Buloke Tree

Traditionally it was accepted that if you veered off a highway at 110km/h and hit a tree within 9m, you could be fatally injured.  The solution was to remove any trees within 9m of the road verge.  Increasingly stringent environmental legislation has made it illegal to remove certain trees. The environmentally friendly solution is to install Wire Rope Safety Barriers (WRSBs) in the pavement verge.

Wire Rope Safety Barrier (WRSB)

So that’s the trees, the birds and drivers looked after.  The benefits of the WRSB seem flawless, unless you are a kangaroo.  Kangaroos are stupid and routinely get cleaned up by trucks and cars.  The issue with installing WRSB is that if a Kangaroo is to jump into the road, they are not as likely to jump out of it when WRSBs are installed.  Areas with the WRSBs have seen an increase in the number of collisions between vehicles and kangaroos.  You’d be forgiven for thinking that kangaroos are a dime a dozen and therefore expendable.  The problem is that they grow to 6ft and hitting one with your car will write off the kangaroo, the car, the WRSB, and potentially yourself.

Public enemy #1

In my opinion, it would seem that the order of importance is planet, followed by people and then maybe profit.  There is no 100% solution to designing out the risk of nature and man crossing paths, but ensuring the sustainability of protected trees and birds is a higher priority than looking after the kangaroos.  It’s no wonder most trucks and utes have bull bars.

Kangaroo defence