@AC - RE: Average speeds = more dangerous
Your "normal" trip appears a little simplistic and has missed out some fundamental elements -
1. Pack family into car. Repeat step one while various children remember vital things like shoes or teddy bears and a final toilet stop.
2. Queue for 40 minutes to get onto the motorway because every man and his wife has decided that a bank holiday weekend is just the time to go for a drive, selfishly depriving you of empty roads for your bank holiday break.
3. Get in the fast lane and do 90mph or you're never going to get to the ferry terminal in the time you allocated by travelling at 80mph. Maintain for 30 minutes
4. Crawl along at 5mph for an hour through the contraflow that the Department of Transport have helpfully set up because bank holidays are the best time to do roadworks as it doesn't stop the proles from going to work to earn taxes.
5. Threaten violence against the creatures you spawned if they don't stop bickering in the back seat.
6. Get in the fast lane and get the ton-up as you're falling further and further behind an already impossible schedule. Maintain for 10 minutes.
7. Slow to 40mph because some moron driving a mini while towing a caravan is trying to overtake an articulated 32-wheeler.
8. The offspring of satan are now demanding a toilet stop at the earliest opportunity, pull into the next service station and threaten that if they're not back in 5 minutes, you're leaving without them.
9. Get back in the fast lane and push te rev counter right into the red zone. Maintain for 5 minutes.
10. Slow to 30mph because the moron in the mini/caravan has miraculously got ahead of you while you were at the services and is now trying to overtake another lorry, this time on an uphill.
11. Exit motorway and join 5 mile queue of traffic through Holyhead
12. Lose all ability to read road signs. Hurl abuse at your children for being a distraction and your wife for being unable to read a 20 year old AA roadmap that doesn't show the town's new one-way system.
13. Arrive at the port to watch the ferry's bow doors closing as it departs without you.
14. Divorce your wife, disown your kids, wait 12 hours to see if there's space on the next ferry.
That was an extract from "Summer Holiday with the Brens"