To harmonise with the E.U. should the U.K. drive on the right hand side of the road?

Answer 1

It would be very difficult and expensive to implement, as all the cars in the UK are right hand drive, and to have everyone driving on the right in right hand drive cars would cause a lot of accidents.

It's not like the UK has any roads that link directly to the rest of Europe, so there's not much point in changing.

Answer 2

No - the cost of such a decision would be phenomenal, (changing all cars over, changing road signs, allowing for accidents caused by people misremembering, changing public service vehicles to allow for boarding from the other side,) and not justified by any real benefit.