Why? That is absolutely the wrong thing to do. Stay in the left lane, unless you are overtaking something in L1. Keep glancing over to L1 of the actual motorway, looking for a suitable gap. Aim to merge into the gap, without causing anyone to need to adjust their speed. Be aware of the possibilty that something overtaking in L2 of the motorway might just be aiming to pull into your chosen gap. Have an escape plan ready should this happen, often it might involve the hard shoulder if the worst happens.
The idea is to perform a last minute merge where the two lanes of the slip become one, then a merge onto the motorway itself. If you are driving a slow vehicle or are a slow driver, you should keep to the left of the slip lane to allow others to overtake. Remember it is usually easier to get out if you have a little too much speed, rather than too little - too enable you to match your speed to L1 and merge more easily. Cars can loose speed much more easily than they can gain it.
The speed limit on a motorway unless signs indicate otherwise is 70mph. That also applies to slip roads. He probably beeped at you because your were causing an unecessary obstruction in L2. The idea is to use the slip road to get upto speed going on and to use it to loose speed going off, which is why they are so long. You should never use L2 (or L3 etc.) except for the purpose of overtaking a slower vehicle - this applies to slip roads too, so you should not have been in the right hand lane unless you were actually overtaking.
Other drivers will not appreciate their smooth progress onto the motorway being disrupted by your perhaps hesitant progress, so please keep to the left where possible, at least until you have gained the skill to make reasonably fast and smooth progress.
It was the original layout for slip roads when they first built motorways in the UK. Some only had one single lane, but two lanes which merge into one is the most common arrangement.
You need to learn to have the confidence to drive with the correct speed to match a gap on the motorway and on the slip road, so you can merge in without causing anyone any problems. The idea is to be able to make your way onto the motorway without any need to do more than make small adjustments to your speed - nice, smooth and predictable progress.
Regarding your final question, uk.rec.driving is one good source :-)
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Regards, Harry (M1BYT) (L)
