Drivers have been cautioned about a little-known rule that could land them with penalty points and a hefty fine. Making a big mistake could cost them over £5,000Katie-Ann Gupwell08:06, 26 Jul 2026Getting in the car every day often just becomes a part of our routine, but there are important rules we need to know about when driving. Something in particular has recently come to light that drivers need to be aware of, as the error needs to be avoided at all costs.‌Plenty of people hit the road during summer to make the most of their time off, but there are several considerations to keep in mind while travelling in cars. There may be various driving regulations you need to familiarise yourself with, as overlooking them could result in costly consequences.‌This isn't the only expert advice motorists have been made aware of lately either. They were also previously told breaking a different rule could lead to a hefty fine.‌The key thing you need to knowBritish roads can be nightmarish during summer. Traffic jams are lengthier, vehicles are sweltering and tempers can be frayed.Perhaps nothing escalates the frustration quite like a motorcyclist weaving through the congestion. To a motorist trapped in the queue, it can appear like queue-jumping and drivers may attempt to obstruct the motorcyclist.However, what numerous motorists fail to realise is that motorcycle filtering is entirely legal in most circumstances, and intentionally attempting to prevent it could result in penalty points, a driving ban and a fine potentially exceeding £5,000 should the matter reach court, according to Dale Gillespie, motoring expert at IronStable.‌Rule 88 of the Highway Code makes it perfectly clear that motorcyclists can carefully filter through stationary or slow-moving traffic. The principle behind this is that it helps ease congestion by removing them from the queue entirely.That's the theory, at least. Yet despite this, numerous riders report regularly encountering drivers who deliberately obstruct their path by pulling across the road or refusing to leave sufficient space to pass."I see this every week on busy A-roads and in traffic jams," said Dale. "A lot of drivers simply don't realise filtering is legal, so they assume the rider is jumping the queue, and that's infuriating for them.‌"But the rider's usually well within their rights, and blocking them is both against the law and dangerous."Risks you need to avoidSo, what actually happens when that weaving biker gets under your skin and you pull across to cut them off? If you're caught, you could find yourself facing careless driving charges under Section 3 of the Road Traffic Act.Obstruction offences could also apply, depending on the situation, and that's no small matter. Careless driving can result in three to nine penalty points on your licence.‌Should the case reach court, a discretionary driving ban and a hefty fine could also be imposed on top of that. That said, this doesn't mean motorcyclists have unlimited freedom to filter whenever they please. They too must comply with the Highway Code.Filtering is not allowed where overtaking is forbidden. Riders must not filter at excessive speeds and they are prohibited from overtaking the vehicle closest to a pedestrian crossing.Care and attention is essential at all times. It's also more challenging on certain bikes than others.Article continues belowA large cruiser such as a Harley-Davidson, with its broad handlebars and heavier build, requires more space and greater caution to filter than a slim commuter bike, meaning riders on bigger machines typically choose their moments carefully."Motorbike filtering can be beneficial for everyone," added Dale. "But it only works if everyone understands the rules."