Assistance advice

The Club’s technical team answers your questions on ‘assistance’ aids

Q My new car has all sorts of ‘assistance’ aids. Can I use these while towing?

A The first challenge is to work out exactly what’s fitted to your car – that’s likely to need a combination of the handbook and brochure/website to check the specification if it’s a current model and close examination of the dashboard buttons (although not all functions have a physical button to turn them off). Then you need to work out what some of the more obscure functions actually do. The road safety charity, Roadsafe, has produced a website to explain many of the common systems (adashub.co.uk), but often your vehicle handbook will be the best reference guide.

In general (unless the handbook advises otherwise), systems which operate by ‘looking’ forward will work (eg anti-lock brakes, automated emergency braking, adaptive cruise control etc) when towing; however, they may not always work as well as when driving without a caravan hitched. The extra weight of the caravan may mean some systems are not as effective – ie stopping distances will be longer and cruise control may not always be ideal with manual cars if the terrain is not that flat. 

Lane monitoring systems (lane departure warning, lane keeping assistance) will probably work but will not allow for the additional width of the caravan. Intelligent speed control (which keeps you to the speed limit) may not adapt to towing-specific speed limits.

Some systems adapt to the presence of the caravan if the car has a good quality towbar installation with vehicle-dedicated electrics – an example is stability control, which often turns into

‘trailer stability control’ when towing. The car will then use individual wheel braking to attempt to correct any instability of the caravan, working alongside any aids fitted to the caravan itself.

Systems which ‘look’ backwards – automated parking, reversing aids, rear cross traffic protection (which stops you reversing out of a parking space into oncoming traffic) will generally switch off when a caravan is connected due to the fact their sensors are blocked by the caravan. 

Other systems probably affected by the presence of a caravan (unless it is narrower than most) include blind spot warning lights, lane change warning systems (which warn or stop you from changing lanes into the path of other traffic) and systems that warn you if you open the door while parked when there’s approaching traffic.

A few manufacturers do provide trailer/caravan reversing aids, such as Land Rover and Volkswagen Group. Sometimes reversing cameras have a ‘wide’ or ‘downward’ setting which can really help when positioning to hitch up, too.

It’s worth noting that while van technology generally lags behind that in cars, the base vehicles used for motorhomes are rapidly gaining similar aids. Smaller campervans will often have much the same capabilities as many cars. Larger motorhomes are perhaps a little less well-equipped, but sometimes have dedicated systems like crosswind assistance – a variant of electronic stability control that keeps a high-sided vehicle in a straight line in gusty winds.

It might not be the most exciting read, but it really is useful to spend some time studying the handbook of a modern vehicle.

Please address your questions to: Technical Information,
Email: technical@camc.com
Tel: 01342 336611

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