Yesterday’s autumn statement wasn’t too much of a shock for hard-pressed motorists, but there’s trouble to come, primarily in the form of the notorious fuel duty escalator being revived.

Tax on road fuel will be raised automatically by the rate of inflation from April next year and the Treasury says it expects to raise an extra £2.3bn over the four-year period to 2020.

Clearly, a policy-decider has figured that oil prices will remain relatively low for the next few years, so drivers will have lost some of the fuel savings of recent times (there’s a huge oversupply of oil at the moment, partly caused by traditional pumpers in the Middle East allegedly trying to choke off America’s new shale gas industry by driving down the cost of a barrel of oil).

Of course, the Treasury, which needs every penny it can get its hands on when the UK is borrowing £78bn this year, won’t just sit by and watch its income from fuel duty gently sink as drivers buy more economical cars and drive them less.

The Treasury also expects to raise £1.4bn by keeping the 3% diesel supplement for company car taxation until 2021, due to ‘the slower-than-expected introduction of more rigorous EU emissions testing’. This explanation doesn’t seem to make immediate sense, but I suspect it is hinting that 2021 will mark a major change in the way motorists are taxed.