On my commute there is a dual carriageway. There are 2 tunnels somewhere along there each approx 200 metres long and theres about a mile of open dual carriageway between the two. Through the length of each tunnel and for a short distance before and after there are double solid white lines down the centre of the road. The highway code says " You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less ." I was told during my advanced driving course to treat such lines as a brick wall. I’m also aware that emergency services have no exemption from this rule. ** SO** if i’m overtaking or filtering i always try and slip into either lane until the lines end then take up where i left off. I do see some bikes fly down the middle of the tunnel and do the lane change thing throughout its length and just wondered what people on here thought, right, wrong, don’t care etc etc! :D:D
from memory only, its a £60 endorsable for crossing a solid white line.
basically it’s teh councils way of saying that they think they road is too hazardous for overtaking.
shouldn’t be done unless it absolutely necesary IMO
Sounds like the A12 to me. I try and stay in the lane but when it’s not safe to do so then I’ll either slow right down or if save cross over. Since it’s virtually gridlock and stationary (or nearly stationary) nearly every night then it seems that if you don’t then you may be increasing the risk to yourself by sitting in traffic and secondly what’s the point of going by bike.
N.B. I always try not to do it under plods beady eye! 
I never cross solid whites… if im going to overtake, i make sure I have enough space to do it without crossing the white line. Solid white lines are there for a reason… they almost always indicate it is unsafe to veer onto the other side of the road. Why take a risk? When your on a bike, the risk you take is with your life.
Also remember that you have less traction to ‘dive back into your lane’ in winter, due to the cold/wet roads.
This discussion was had before, but think the problem came with the definition of stationnary. It is does not apply to a car that is just not/hardly moving, it refers more to parked cars in this case, but that was the basis of the heated discussion that followed.
Also know the stretch you are talking about, although each time I have been through there, the traffic has been moving fairly freely so it has not been an issue.
What about if you can overtake a car but dont cross the white line, is that OK?
I’m not sure, but I think that in the abscence of a no overtaking sign then it’s ok so long as you don’t cross the lines
I’ve just looked it up (I’m long term sick remember, you’ll be suprised what can excite me these days:D ), and as far as I can see Regulation 26 of the Traffic Signs Regulations and General Directions 2002, which details the definition of the solid white lines (although the offence committed is actually contrary to Sec 36 of the Road Traffic Act 1988 - failing to comply with a traffic sign)
it only mentions crossing the white line - not overtaking, so it would appear you can overtake so long as the white line isn’t crossed…
I would cut & paste the regulations but it takes up so much space I’m not going to bother…
there’s a link here http://www.opsi.gov.uk/si/si2002/20023113.htm#26
for the regulations… and here for the part of the Road Traffic Act that applies
http://www.opsi.gov.uk/acts/acts1988/ukpga_19880052_en_3#pt1-pb9-l1g36
sadly the sources above don’t include the case law my source has… but enjoy:)
nice one fella!
Just a thought - I believe you are allowed to cross double whites to overtake ‘slow-moving’ vehicles, horse-drawn, hedge & verge mowers, etc. Cars in the A12 tunnels are frequently much slower than that (trust me, I’m there twice a day) so does that make them ‘slow-moving’? In practice, they are pretty good about giving you room to pass without changing lanes.
Also, though there’s nothing in the regs to differentiate between them, I would be much more hesitant about crossing double-whites onto the other side of the road (it would have to be exceptional circumstances) than I would be about using the white-lined space between two lanes going in the same direction.
Just keep between the two solid whites when they start and don’t exit out either way until they become dashed.
DONE! 
You’re correct in that there is an exemption but it’s only as follows and quoted earlier, “You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less.”
I agree too that the majority of cars do move over and allow bikes through.
Johnse1 hit the nail on the head in my opinion as the Road Traffic Act states crossing the white lines.
I’ve done this commute 4 days a week since 1997 which was before that part of the A12 opened (correct guess, whoever it was!) so i’ve seen all kinds of approaches to the tunnel conundrum!!!:D:D:D
Hmmm… solid white lines used to be there for a reason.
These days more and more councils are sticking them everywhere, effectively dumbing down driving.
They seem to think that all drivers are idiots and cannot make decisions themselves, so the nanny state will make their decisions for them.
Scotland is a pretty good place, along with Cornwall - double whites where vision is obstructed / blind bends etc, then when the view of the road opens up, the lines stop.
Went on a trundle round Dorset in september, and a long stretch of road towards Weymouth has had the double white treatment - despite being in the country, well surfaced and with visibility for miles.Utterly pointless.
Give that man a pint!
I was on the A12 the other day through those bits. As traffic is rarely “stationary” I wouldn’t cross the lines, as the second it moves whilst you’re overtaking you’d be breaking the law. I didn’t have a problem overtaking within the lane where the road was wide enough.