What a ‘risk-based approach’ really means for temporary traffic management


Civil Contractors New Zealand Technical Manager Michelle Farrell observes a real-life scenario of temporary traffic management and how it aims to reduce risk, but in some ways achieves the opposite

The activity is footpath construction on two corners of a no exit street, off a side street, off a very busy Auckland urban road. The Code of Practice for Temporary Traffic Management (CoPTTM) dictates a 30km/hr temporary speed limit, shoulder closures, pedestrian detour and up to 100m taper in each direction. The TTM workers did a nice job of setting out the cones and signs and were pleasant to deal with while the road needed stop/go on the first day. They worked long hours in the fierce sun and were first onsite and last to leave, as you’d expect.

Several days later, during a long weekend, I was passing by and noticed several hazards had occurred, so I took the opportunity to look at the picture with a wider lens. Some might say I did a quick risk assessment. I noticed the following risks.

Several signs had blown over in the strong winds we had, with two blocking the footpath (a busy access road to a popular beach) – now hazards for pedestrians and children on bikes. An elderly man was seen struggling to move a sign blocking his driveway. The pedestrian detour signs had blown over, making the setup unclear.

With approximately 300m of residential road affected by the CoPTTM-prescribed cone layout, the workers supposedly had to knock on doors (time consuming) to get residents to move vehicles off the street for several days (it’s usually packed with parked cars) – potentially congesting other narrow local roads. Some vehicles owners apparently couldn’t be contacted, and several vehicles remained parked in the coned off areas throughout the works.

Cars drove through the area at speed – by removing parked cars either side of the road, the usable carriageway width is significantly wider, meaning vehicles are travelling faster with the TTM in place than they would on a normal day. Later during the long weekend when the weather cleared, all the cones delineating the no parking taper along the whole road had been moved aside and cars lined both sides, as public blatantly ignored what was perceived as unnecessary TTM to access the popular beach.

To summarise some risks that were observed during a three minute walkover (i.e. what can I see here that could potentially become a hazard?): high winds knocking over signs, therefore lack of signs making the directions to road users and pedestrians unclear; signs and cones being hazards in themselves; vehicle drivers ignoring the temporary speed limit and in fact travelling faster than usual due to increased carriageway width; public moving cones to park cars in zones that were supposed to be blocked off.

It occurred to me, that the TTM in place (in accordance with CoPTTM) may have been achieving the opposite of its intention, due to the particular situation.  What is the purpose of the long taper of cones? Would removing these cones increase risk to anyone? Or would it in fact decrease the risk of road users ignoring temporary speed limits, moving TTM out of the way and potentially becoming more desensitised and disrespectful. In turn potentially leading to abuse of the TTM staff.

Could the work be planned differently (timing, staging, construction methods) to avoid TTM being in place for longer than needed? Is a shoulder closure necessary, or would a bulky physical barrier (eg a small truck) parked in front of the works actually provide better protection for the workers? Is the unattended site’s TTM working as intended, is it necessary or is there a better way of doing it?

It seems to me the required CoPTTM setup is potentially creating more risks in this scenario than the works themselves. And if an incident occurred due to this set-up, who would be held responsible?

If we treated traffic management in the same way we treat other high risk activities in a public urban residential area, we might see someone coming to site to view what the street usually looks like (parked cars on both sides, traffic forced to slow down due to this narrowing effect and a busy beach access, including for children on bikes); they might consider the proposed timing of the works (the day before a four day summer weekend beside a popular Auckland beach) and wonder whether the works could be staged on either side of the weekend; they might consider bulky physical barriers to protect the works and to force road users to both slow down and go around the works; they might even realise that letting the cars stay parked along the ‘taper-zone’ where works were not actually happening could help calm traffic, rather than hinder the works.

Often this information isn’t available during the planning stage and when the contractors turn up to site to start the works they might notice other risks, such as the high winds or the increased carriageway width or realise that delays have occurred to the works starting and now the works will straddle a 4-day weekend. A pre-start or quick toolbox meeting held in the morning, including the physical works contractor, the STMS, and perhaps a client representative could identify these new risks together and collectively make a decision of how best to minimise them.

The decision would then be appropriately recorded and communicated to anyone affected by the changes, perhaps with a note for the STMS to keep an eye on one of the controls (how are pedestrians acting for example, is the layout working as intended?) and to give the contractor project manager a ring if they’re concerned. Actually, it reminds me a bit of the three C’s: “consultation, cooperation and coordination” as well as Worksafe advice that a risk-based approach can help parties “reach a common understanding and establish clear roles, responsibilities and actions”.

Some food for thought, as we try to understand how the risk-based approach can be applied to temporary traffic management. Who needs to be involved in these decisions and at what stage? What processes are in place, or need to be added for success? How do we make it easier for people to make smarter decisions based on the specific environment and activity they’re working in and not just lay out cones according to a book and a traffic management plan they’ve been handed for the first time that morning.

And remember, both the contractor and the TTM provider in this case have  followed their long-practised approach of applying stock-standard thinking and done everything just as they should under CoPTTM, this is in no way a poor reflection on them. This is why it’s time for a change.


Pssst – what do they mean by a risk based approach for temporary traffic management? | Civil Contractors NZ