The hour to an hour and a half it takes to drive to Shannon is more than compensated by the time/hassle saved doing preflight US customs and immigration. If there was a decent motorway between the two cities you would do the journey in 45mins. If you ever watch a 757 taking off from Shannon they use most of the runway which is 1km longer than Cork's, so for anyone saying that a fully laded A332 can take off safetly, I say check again. No margin for error.
