Behaviour by a small number of cyclists and motorbike riders is concerning the National Road Carriers Association.

NRC CEO David Aitken says a small percentage of cyclists and motorcyclists appear to have an "arrogant" attitude to traffic and expect it to make way for them under any circumstances.

"Perhaps they don't realise that heavily-laden trucks take longer to take evasive action, change direction, or brake and come to a stop," he adds.

Aitken points out that trucks have blind spots in the front and sides as well as at the rear – particularly on the left-hand side where cyclists ride up at intersections and can't be seen.

"Other road users should not always assume truck drivers can see everything that's happening around them," says Aitken, who points out that incidents between motor vehicles and cyclists or motorbikes "usually see the cyclist or motorbike rider come off second best.

"We know those forms of transport are often quicker in inner-city traffic, especially at peak hours," says Aitken.

"We respect their right to be on the roads – but they have to be as respectful of other traffic as any other vehicle."

He says some NRC members are recreational cyclists and appreciate the inherent danger in riding on the road: "We know that if we have an incident with a motor vehicle we're going to come off second best and it's going to hurt."

The safest place is probably in the view-line of the mirrors of a truck. Some trucks will have a sign saying: "If you can't see me in my mirrors, I can't see you," Aitken points out, and adds: "It's a really good rule and a simple one for a cyclist to understand."

Problems with motorcycles occur more often on motorways during peak hours, when riders weave between slow-moving traffic at higher speeds.

"Truck drivers can't always be looking in their rear vision mirror for bikes coming up behind," says Aitken: "Drivers do have to look at where they're going."

Efforts to get more solo commuting motorists out of vehicles and onto cycle lanes and free up roads for commercial traffic have been welcomed by NRC.

"But then we have the situation where the cycle lanes are taking up valuable space that might be used by another lane for vehicles. It's a difficult situation."

He suggests that the solution in some areas might be to install cycle lanes on roads that run parallel to the main route, but that don't attract the same volumes of traffic.