*** L is for Lane Discipline ***
You should always follow lane markings, which are there for 2 reasons:
They make the best possible use of road space
They guide the traffic.
Keeping to the lane markings is vital.
Position yourself in good time
If you find you're in the wrong lane, don't try to change by cutting across other drivers at the last moment. Carry on in your lane and find another way back to your route.
Position your vehicle according to your route. Always check your mirrors, and if necessary take a quick sideways glance to make sure that you will not force another road user to change course or speed. When it is safe to do so, signal in good time and when clear, move out.
Never weave from lane to lane
Never straddle 2 lanes
Never change lane at the last minute
Always stay in the middle of your lane until you need to change.
In heavy or slow moving traffic - Don't:
Change lanes suddenly
Keep changing lanes
Straddle lanes or lane markings
Weave in and out
Obstruct 'Keep Clear' markings. Check for these in congested, slow moving traffic, eg, at exits for emergency vehicles.
Cyclists moving up the inside
Large vehicles needing to straddle lanes before turning
Keep to the left hand lane wherever possible. Don't use the right hand lane just because you are travelling at speed.
On a carriageway with four or more lanes, don't use the lanes on the right unless signs or markings allow you to do so. Peak hour 'tidal flow' systems might permit or forbid use of these lanes, depending on the time of day
Bus and cycle lanes
These are separate lanes shown by signs and road markings. Do not enter these lanes unless permitted by the signs.