Whether you drive a car, truck or bus, or ride a motorbike, heavy winds can cause a lot of extra danger. This article explains the hazards you could experience during and immediately after heavy winds, and their effects on other road users.
The capital of windiness in New Zealand is Wellington, but there are plenty of other exposed places where you can be subjected to strong crosswinds that will make it challenging to stay safe on the road.
The Road Code does contain some information about the challenges of winds, but only in relation to buffeting by heavy vehicles when riding a motorbike, therefore we’ll flesh it out with more concepts and guidelines here for cars, motorbikes and heavy vehicles.
As you can see from this video, high winds can be catastrophic for some vehicles:
It’s not just crosswind that can affect trucks: headwinds can cause rapid loss of speed on inclines, and tailwinds can make braking more challenging.
Tankers that carry bulk liquids, oversized vehicles with top-heavy loads, and empty trailers are much more at risk when cornering into a crosswind because as the truck turns, the forces that already act on the vehicle to tip it over are exacerbated by the crosswind. You will need to drop your cornering speed in a strong side wind.
If you are loading your truck, keep loads low and central, and plan routes that avoid exposed areas.
The Road Code for motorcycles says:
A heavy vehicle coming towards you creates a wave of air. This can affect your stability, so move to the left of the lane where you will be least affected.
Also be prepared for cross winds when emerging from the protection of buildings, trees or banks. Cross winds can affect your balance, especially if your motorcycle is heavily loaded or fitted with a large fairing.
Your riding style is important so that you stay in control of your bike. With only having two wheels you will be more unstable, and your turning is affected by which way your motorbike is leaning. There are a few techniques you can use to cope with high winds.
- Grip the petrol tank with your knees and keep your arms fairly loose. The tight grip by your knees is aerodynamic and keeps you well-settled on the bike. It can help to keep your weight more over the peg that’s facing the wind.
- The loose knee or flapping knee is where you let your knee stick out on the side of the bike that faces the wind – remember to keep your foot on the peg. The knee acts like an air brake, helping pull the bike towards the direction the wind is coming from, and balancing out any tendency for you to turn away from the wind. When you perfect this technique you’ll find that the knee will automatically move to be at the right resistance for you.
- Keep your bike upright and slightly hang off your bike in the direction the wind is coming from. This maintains the centre of gravity without you having to lean the bike.
If the wind is really strong you can look for an alternative route home that avoids exposed places, or you can walk with your bike.
Fairings and aerodynamics
Minimising your profile and wind resistance will help you reduce the effects of the wind. You should not adjust your position so that you can’t control the bike effectively, but you might be able to crouch down slightly (particularly when travelling headwind).
If you are carrying luggage make sure it’s kept as low as possible and is strapped down well. It’s better to try to strap a backpack to the pillion seat or put its contents in panniers rather than wear it because this lowers the centre of gravity.
If you have fairings, they can really help in headwinds, but can catch the wind in a side wind.
Close your visor and make sure your zips on your jacket and your jacket’s pockets are done up – you don’t want mini parachutes forming in your clothing. This also stops you from being buffeted around so much – if you are moving around in the seat, your movements will be translated to steering inputs.
If it’s wet and windy then areas that are usually slippery become more hazardous, including cattle grids and railway tracks. Because these areas have less grip than regular tarmac, a strong gust can blow you sideways.
The gyroscopic effects of your wheels will help keep you upright, so if you ride too slow you will become more unstable. But if you ride too fast, if you are blown off course then you will travel further before you can correct it.
As you come to a stop at an intersection or traffic lights you will have to steady yourself against the direction of wind, and this might involve using both feet to steady the bike. You will need to be careful if you are on an uphill slope because the front brake alone might not stop you from rolling backwards.
Questions in the theory test:
Cars are not usually badly affected by crosswinds. They will be buffeted around a bit, but there’s little risk of them being tipped over except in the kind of tropical typhoon or tornadoes that don’t happen in New Zealand. The problems come with cars towing high-sided trailers, top-heavy trailers and lightweight caravans; unladen vans, and motorhomes.
If you are towing a caravan try to plan a route that avoids exposed areas, or delay your journey. If you feel your trailer start to tip, turn towards the direction of the tipping if it’s safe to do so.
Other road users
Pedestrians, cyclists and motorcyclists are at the most risk in the wind. Cyclists and motorcyclists sharing your lane can be blown about and into the path of other vehicles. If you are overtaking them, give them more room. Pedestrians can be blown into the road in extreme cases, and if there is driving rain pedestrians might be dashing to get across the road without looking properly.
This video shows cyclists struggling against the wind.
Debris can be dangerous even after winds have died down. Strong winds can pick up signs and other sharp debris which can hit other road users – this is particularly dangerous for motorcyclists. Winds can also blow trees over and dislodge branches which are difficult to see at night.
If power lines are brought down they can be laying over the road.
If you are riding along the coast, the wind can blow salt water onto the road which is corrosive to your vehicle – this has been a problem in the past on Tamaki Drive and the North-western motorway causeway between Waterview and Te Atatu, and doubtless in other places.
Where do strong winds occur
Strong winds can occur anywhere, but often the natural landscape or buildings break up the gusts. This means that you can be driving or riding in an area that doesn’t seem that windy – for example, where there are tall buildings, and when you emerge from the lea (shadow) of the building, you can be hit by a strong crosswind.
For example, if you are driving along SH1 out of Auckland City towards the North Shore you will have to go over the Harbour Bridge. As you wind your way around Westhaven, there are cliffs and sound barriers to break up the wind flow, but as you start driving up the bridge it becomes much more exposed and crosswinds can become a problem.
Exposed motorway overpasses, areas where there’s not much vegetation to stop the wind, high-altitude roads and coastal areas can all be hit by strong gusts.