Filtering Part 2 – Motorways


With traffic moving much faster on motorways the perception of speed changes. If all the traffic is doing 40 miles per hour then it can feel very slow. But you are still moving at about 60 feet per second, or 19 metres. If you pass the traffic at 50 miles per hour and make the differential just 10 miles per hour then you may think it’s okay.

The fact is at that speed you risk being pulled in for careless riding. Travelling at that speed between lines of traffic renders your decision to be that of ‘undertaking’ traffic contrary to the rules of overtaking, rather than filtering. At 50 miles per hour it will take you something like 175 feet or 53 metres to stop, longer in the wet, and you will be likely to be run over if you come off.

All three lanes on the motorway are there for our use but when the traffic is at a virtual standstill where is the best place to filter?

Without going into all the possibilities that may or may not occur it is generally safer to filter between the traffic in lanes 2 and 3. Do not filter between lane 3 and the central reservation. Filtering between lanes 1 and 2 is okay but usually there will be many more traffic movements across your path as drivers jostle for position to leave and join the motorway. If you choose to filter in between lanes 1 and 2 then you will need to take extra care.

This is compounded by the problem that lorries are in lanes 1 and 2 making you less obvious or invisible to car drivers that are changing direction from those lanes. In my experience lorry drivers are very helpful to riders on motorways so in many respects you don’t have to worry so much whether or not they’ve seen you, just worry about whether you can fit between two lorries! Another reason why filtering between lanes 1 and 2 isn’t so good.

Be patient. Stick to the ‘golden rule’ and the rules of the Highway Code.

The Highway Code

Filtering comes into the category of overtaking so all the rules of overtaking apply. If you don’t ride in accordance with the rules of the Highway Code you risk being prosecuted. Do take advantage of the size and manoeuvrability of the bike to filter through congested traffic but bear in mind a few key points:

Ride slowly and always be ready to stop; look out for vehicles changing lanes; in high streets watch out for people getting in and out their vehicles, or vehicles stopping suddenly; pedestrians and cyclists have as much right to use the road as everyone else so take care, their behaviour can be unpredictable; junctions to the right and left should be in your plan as should gaps in traffic; it’s easy to think that a gap is big enough for you to ride into or turn into…… but…’What if? there is someone crossing the road that you can’t see; or maybe another driver is letting someone out of a driveway and you can’t see that yet either; always ask yourself why the gap is there.

You must comply with road markings ****

…such as zebra crossings, solid white line rules and box junctions. Before you filter, make a plan and use the system of riding by making rear observations with the mirrors or a lifesaver if necessary, consider whether or not you need to signal, make your manoeuvre, take into account your positioning during the manoeuvre, use the golden rule to measure your speed, keep looking and be prepared to change your decision and act on it if necessary. Only go out if you know where you’re coming back in.