Roadworks: Flying chips and other hazzards

Ever been frustrated by seeing roadworks signs with temporary speed limits when there’s no work happening? Have they been left up by mistake, so can be ignored?

Well, no, say those who maintain our roads. New Zealand Transport Agency (NZTA) regional transport systems manager Mark Owen says there are two reasons for temporary speed limits at roadworks: for protection of road workers and for protection of road users.

“The speed limit is to flag to road users that there is a risk in terms of the activity that is happening, or that something has changed to the road environment whereby they need to take a bit more caution and travel at a lower speed,” Mark says.

He explains the temporary speed limit depends on what is happening at the site; 30km/h if road workers are present, if the road is reduced to one lane, or there are Stop/Go controls. Limits of 70km/h or 80km/h are used on open roads where barriers physically separate road workers and traffic. Lower speeds are still needed in those situations because lanes may have been narrowed or alignment changed, and there will be a lot of distraction off to the side.

Another high risk is small areas of the road with no seal which, Mark says, could catch someone out, particularly at night. He says all road users must be considered, including motorcyclists and cyclists, who could lose control on a patch repair that would not affect a car driver.

“It’s got to be a speed which is safe for all,” Mark says. According to the AA’s quarterly Member surveys, one of the top annoyances is driving through temporary speed limits when there are no road workers in sight. The NZTA explains that even when the bulk of repairs have been completed, a temporary speed limit will be left in place because the surface may have loose chip seal and no road markings, meaning the edge of the road can’t easily be seen at night.

Another key reason is that new surfaces need to be bedded-in. Driving at high speed over new surfaces causes damage and can mean they need to be re-laid, which means speed restrictions are in place for even longer. “A new chip seal surface, which is something people are going to see a lot of over summer, can typically take one to two days to ‘roll in.’

The traffic does that for us. In the interim, there could be a lot of loose chip flying around, but lower speeds prevent chips from flying up. It’s also important to avoid heavy braking or manoeuvring while the surface is still tender.” For that phase, the temporary speed may be lifted to 50km/h and only returned to the normal speed limit after the road is swept clean of lose chip seal and the surface markings have been re-instated. But that won’t always be possible if there are still other hazards in place, Mark says.

“Often it is something off to the side that road users don’t necessarily see. It might be a big drop-off on the side of the road. If that’s high-risk and there is no shoulder, we may leave the 30km/h sign out,” Mark says.

Weather can also be a factor. After a section of road has been prepared for sealing, rain can degrade the repair and the exercise has to be repeated.

“Lower speed signs can be out there for several days waiting for the ideal climatic conditions to put a good seal down.” This is why New Zealand roadworks predominantly occur during summer, as our common chip seal surface needs to be done in temperatures above 10 degrees. If the temperature drops significantly within a month of having new chip seal surface laid, the new surface might not ‘take’.

The Insurance Council says insurers see a spike in claims for windscreen breakages during summer. They are concerned about the increasing cost of windscreen repair due to advanced safety technology that has sensors and cameras bonded into the windscreen.

John Lucas, Insurance Manager at the Insurance Council, explains that when a windscreen is replaced, the sensors have to be re-calibrated.

“Windscreen insurance claims have significantly increased over the last few years. This is a cost to insurers so it will ultimately be reflected in premiums. Plus there is the increased inconvenience to owners of being without a car for a few days if it has to go back to the authorised dealer for calibration.”

He implores drivers to slow down at roadworks and obey the temporary speed limits. “You may not break your windscreen but you may break someone else’s by driving too fast and flicking up loose chips.”

Civil Contractors, who represent the various companies that undertake roadworks, report the majority of crashes at roadworks sites involve people driving through.

Technical manager Stacey Goldsworthy believes there is a general assumption that if there are no workers around, there is no reason to slow down. “The misconception is that the temporary speed limits are to protect the workers alone, but they are just as much for the safety of road users, if not more so in certain circumstances.”

Stacey says a high number of crashes are due to loss of control with speed as a contributing factor. But in the last 12 months there has been four fatalities involving road workers and the industry is looking at what else can be done to better protect them. Stacey says the ideal option for contractors is to close the road.

“This enables work to be done not only safely but efficiently, delivering the best value-for-money outcomes. However, most of the time this isn’t an option so additional controls focus on providing road users with early warning.”

These include remote-control traffic signals which remove the need for workers to stand on the side of the road holding Stop/Go signs, and variable message signs to help make it clear to motorists why they need to slow down.

But Mark Owen of NZTA cautions: “It’s very hard to convey to people in a short space of time, as they pass a point, that there is a risk ahead – beware of drains, drop-offs, whatever it may be. The key thing is to provide them with traffic management which guides them through the site safely.”

The Transport Agency is doing more roadworks at night when it is less disruptive to traffic. In some cases they will close roads completely overnight, with detours in place, so contractors can get more work done without the interruption or hazards of traffic. Mark says night closures impact a smaller number of road users.

“It is far safer for our road workers and better for road users not to have to go through a whole lot of roadworks sites during the day.”

The Transport Agency is also investigating trialling ‘point to point’ speed cameras on a large roadworks site as a way of encouraging compliance. They measure the average vehicle speed between two fixed cameras and are common in Europe and Australia. 

Even if road workers aren’t on site, slow down. Why?

· The road surface is still loose

· There are no lane markings

· There may be unseen hazards just off the road