Can You Drive on the Motorway With a Roof Box?
Yes, you can drive on the motorway with a correctly fitted and appropriately loaded roof box. Motorway journeys are one of the most common reasons people hire roof boxes in the first place, particularly when heading on a family holiday, driving to an airport or beginning a longer trip to Europe.
There are some differences to keep in mind, though. A roof box adds weight and changes the aerodynamics of your vehicle, so sensible loading, secure fitting and appropriate driving become particularly important at sustained motorway speeds.
If you're hiring from Midlands Roof Box Hire, professional fitting is included. Here's what you should know before joining the motorway.
Is It Safe to Drive With a Roof Box on the Motorway?
A suitable roof box can be used for motorway travel when it has been correctly installed, loaded within the applicable limits and used in accordance with the equipment and vehicle manufacturers' instructions.
Before setting off, make sure the roof box is securely mounted, properly closed and locked. The luggage inside should also be appropriately distributed and secured rather than being able to slide freely from one end of the box to the other.
Our guide Does roof box hire include fitting? explains more about the professional fitting included with our hire service.
How Fast Can You Drive With a Roof Box?
Having a roof box fitted doesn't create a special UK motorway speed limit of its own, but that doesn't mean you should automatically drive as fast as the general limit permits.
You must comply with the speed limits applying to your vehicle and road, while also following any maximum-speed or usage guidance supplied by the manufacturers of your vehicle, roof bars and roof box.
Your speed should always be appropriate for the conditions. Traffic, rain, high winds, visibility, the weight you're carrying and the way the vehicle feels can all justify travelling more slowly.
If you're driving outside the UK, check the current rules for each country on your route rather than assuming British motorway rules apply.
A Roof Box Changes the Aerodynamics of Your Car
Without a roof box, air flows around a vehicle in the way its original body shape was designed to manage. Adding a substantial box above the roof changes that airflow and increases aerodynamic drag.
You may notice this more at motorway speeds than when driving around town.
One consequence can be increased fuel consumption or reduced electric-vehicle range. The exact effect varies considerably according to the vehicle, box, load, speed, weather and driving conditions.
We've covered this separately in Do Roof Boxes Reduce Fuel Economy?.
Be More Conscious of Crosswinds
A roof box increases the surface area presented to the wind. On exposed motorway sections, bridges and open countryside, strong crosswinds may therefore be more noticeable than you're used to.
Pay attention to weather warnings and roadside signs, keep both hands ready to control the vehicle and adjust your speed appropriately for the conditions.
You may also notice a change in airflow when passing or being passed by large vehicles. Smooth steering inputs and leaving appropriate space are preferable to abrupt reactions.
Leave Yourself Plenty of Space
A holiday-loaded vehicle may be carrying considerably more weight than it does during an ordinary commute.
That includes luggage in the boot and passenger compartment as well as the roof box, bars and their contents. Stay within all applicable vehicle and equipment weight limits and take the vehicle's load into consideration when driving.
Maintain an appropriate following distance and increase it when road or weather conditions require. Avoid harsh acceleration, braking and sudden changes of direction wherever reasonably possible.
Pack the Roof Box Before You Think About the Motorway
Safe motorway use starts on the driveway.
A roof box should not simply become the place where everything that wouldn't fit in the boot gets thrown at the last minute. Think about the weight and position of the contents, distribute suitable luggage sensibly and secure items appropriately.
Particularly heavy belongings may be better positioned low down inside the vehicle where suitable, subject to the vehicle manufacturer's guidance and applicable load limits. Roof storage is especially useful for suitable lighter and bulkier luggage.
Remember that available volume and permitted weight are two different things. A Extra Large 580-litre roof box may have plenty of unused physical space even when you have reached the applicable weight limit.
Should I Check the Roof Box at Motorway Services?
For a longer journey, a motorway service stop is a convenient opportunity to carry out a visual check of the setup.
Once safely parked, check that the box remains properly closed and locked and that nothing appears loose, damaged or out of position. Follow any checking or retightening instructions provided for the particular equipment you're using.
A check early in a long journey can be particularly useful after the vehicle has travelled its first substantial distance with a newly loaded roof box.
What If the Roof Box Starts Making a Noise?
Some additional wind noise can occur when roof-mounted equipment is fitted, particularly as speed increases. What you shouldn't do is ignore a new or unusual sound that suggests something may have changed.
If you hear persistent rattling, movement or another concerning noise, don't attempt to diagnose it while continuing at motorway speed.
Leave the motorway or stop somewhere safe when possible and check the equipment. If you're using hired equipment from us and you're concerned about the setup, contact us for advice rather than continuing with something you believe may be insecure.
Can You Overtake With a Roof Box?
Having a roof box doesn't prevent normal motorway driving or overtaking, but remember that your vehicle is operating with additional weight and altered aerodynamics.
Plan manoeuvres properly, use appropriate observation and signalling, and allow sufficient space. Be particularly conscious of windy conditions and the airflow around larger vehicles.
The roof box should become something you account for in your driving rather than something that causes abrupt changes to it.
Does a Roof Box Affect an Electric Car on the Motorway?
The same aerodynamic principles apply to electric vehicles. Because aerodynamic resistance becomes increasingly important at higher speeds, a roof box can reduce the distance an EV travels on a charge.
If you're making a long motorway journey, allow for the possibility of reduced range when planning charging stops rather than basing the entire route on the range you normally achieve without roof-mounted equipment.
Actual consumption will depend on the particular car, box, speed, load, weather and journey.
Can I Drive in Heavy Rain With a Roof Box?
A properly fitted roof box can be used in normal wet-weather driving, but poor weather should influence how you drive regardless of whether a box is fitted.
Reduce speed when appropriate, increase the distance between you and the vehicle ahead and respond to the road and visibility conditions.
Our premium Thule roof boxes provide enclosed, weather-resistant storage, but particularly moisture-sensitive belongings should still be protected appropriately inside the box rather than assuming any roof box is an absolutely waterproof container.
Remember Your Vehicle Is Taller
Height isn't normally the main concern while you're actually on an open motorway, but it becomes relevant as soon as you leave it.
Service areas, hotels, multi-storey car parks, underground parking and other destinations can have height restrictions. Your normal vehicle height no longer tells the whole story once the bars and roof box have been installed.
Know the approximate overall height of the complete vehicle and pay attention to restrictions throughout your trip.
Motorway Driving Before a Ferry or European Holiday
For many of our customers, the motorway is only the first part of a much longer journey.
If you're driving towards Dover, Folkestone, Harwich or another international departure point, remember that your roof box can also affect the dimensions you need to provide when booking vehicle transport.
If your journey involves a ferry, Can You Take A Roof Box On A Ferry? explains what to consider. You can also read Can You Take A Roof Box To Europe? if you're continuing your journey abroad.
Choosing Enough Space for a Long Motorway Journey
One of the advantages of roof box hire is that luggage doesn't have to take over the passenger compartment just because you're travelling further from home.
Our Large roof box provides around 470 litres of capacity, while our Extra Large option provides around 580 litres. We also supply suitable setups for a wide variety of cars, including Volvo, Audi, VW, Toyota, Hyundai and BMW models.
Where compatible supporting equipment is required, Roof Bar Hire is also available.
Before Joining the Motorway
A quick pre-journey check is worthwhile before a long drive:
- Make sure the roof box is properly closed and locked.
- Confirm that the fitted equipment appears secure.
- Check that suitable luggage has been distributed and restrained appropriately.
- Stay within the applicable vehicle, bar and roof-box load limits.
- Remove the key from the roof box lock.
- Keep important journey items somewhere readily accessible.
- Know the approximate overall height of the fitted vehicle.
- Follow any speed and usage guidance applicable to your particular equipment.
- Adjust your driving to traffic, wind and weather conditions.
Motorway-Ready Roof Box Hire in the Midlands
Midlands Roof Box Hire supplies professionally fitted roof storage for holidays, weekends away and longer motorway journeys. Customers travel to us from Lichfield, Bromsgrove, Solihull, Burton-upon-Trent and Coventry, with our main base in Tamworth.
Browse our Roof Box Range to compare your options, see How much does it cost to hire a roof box? for current pricing or read Is it cheaper to hire or buy a roof box? if you're deciding whether hiring makes sense for your journey.
Motorway Driving With a Roof Box Is Mostly About Preparation
A roof box doesn't stop you using the motorway. What matters is that the equipment is suitable and correctly fitted, the load is appropriate and secure, and the driver remembers that the vehicle is now carrying additional weight with different aerodynamics.
Prepare properly before leaving, drive according to the conditions and check the setup appropriately during a long journey. That allows the roof box to do what you hired it for: carry suitable luggage while leaving more useful space inside the car.
Contact Us with your registration, hire dates and requirements if you'd like to arrange professionally fitted roof box hire for your next journey.