As mentioned above - remember that the Autumn Statement is not automatically law. All of the proposals in it have to be discussed, formalised into white papers, discussed again, and be voted on before they become active law. If there's no will in Parliament for any of the proposals, then they won't happen in the proposed form.
The other thing that I think certain sections of the media are guilty of is assuming that VED has anything to do with roads. We haven't had 'Road Tax' since Churchill abolished it in the 1940s. Roads (in general) are built and maintained by councils - and hence funded from Council Tax. Major road schemes and motorway maintenance come out of Department of Transport funds, which come from general taxation (VAT, Income Tax etc). VED is called 'Car Tax' because it's a tax on car ownership (and until now, pollution), which also goes into general taxation Treasury funds. So indirectly yes, it does fund some road maintenance, but it's not a direct link.
