London to Glasgow, four hundred miles up the western side

Most of this journey is unremarkable and one section of it is genuinely wonderful. From junction 36 the M6 runs along the eastern edge of the Lake District, climbs to Shap and drops towards Carlisle with fells on both sides and almost no traffic.

Passengers who have only ever done this journey by train or plane are usually surprised by it. It is the one part of a nine-hour drive that nobody sleeps through, and it is the reason the western route is more pleasant than the eastern one despite being no faster.

The high point of the M6 sits above a thousand feet and it holds weather that the valleys either side do not. Snow closes or slows it several times most winters, and it is the section that decides whether a January run to Scotland takes eight hours or eleven.

We check it specifically rather than looking at a general forecast, and where it is genuinely bad the honest answer is to delay the departure by a few hours or to reroute east. Neither is a failure; pressing on over Shap in snow with passengers would be.

Glasgow is one of very few British cities with a motorway driven straight through the centre of it, and the M8 carries a remarkable amount of traffic across the middle on elevated sections and through cuttings.

It is quick outside the peaks and slow inside them, and the junctions come up fast with short slip roads. For a destination in the West End or on the south side it is worth leaving the motorway earlier than a screen suggests.

A good share of these journeys keep going. Turnberry and Troon are an hour south-west on the A77, Loch Lomond half an hour north-west, and the road to Inveraray and the west coast continues from there.

For those destinations the car has an argument that the city does not. Trains reach Ayr and Balloch; they do not reach a golf resort, a lodge on a sea loch or a wedding at a country house on the Cowal peninsula.

Seven and a half hours in one direction is a full day. There and back inside a day is not something we will do with a single chauffeur, and any operator who offers it should be asked how.

The arrangements that work are an overnight for the driver in Scotland, two drivers sharing the run, or a one-way road journey with the return by train or air. Each is priced differently and the quotation says which one it assumes.