Holyrood’s connectivity committee said a major funding boost was needed because current spending was insufficent to prevent conditions deteriorating.
It also called on ministers to devise a new way of ensuring the extra money was used for improving roads.
Councils are responsible for all but motorways and other trunk roads, but oppose funding being ring fenced, the committee said.
MSPs want a new push towards tackling the problem in the form of a “national transport improvement project” that would also cover pavements and cycle lanes, and “more robust” inspections.
The “package of action” would be to “significantly reduce the maintenance backlog over a defined period”, funded by “substantial additional investment” in road maintenance.
Committee convener Edward Mountain said: “The committee is concerned there is an estimated £1.2bn backlog for maintenance of trunk roads, the main arteries of Scotland’s roads network, and around £1.8bn needs to be spent to bring the local roads network up to a satisfactory standard.
“Whilst the committee acknowledges the pressures on local government budgets, it is clear not enough has been spent on local roads over a number of years.”
Neil Greig, Scotland-based policy director of the IAM RoadSmart motoring group, said: “This should be a wake-up call to councils and the Holyrood government that they need to get a long-term plan in place urgently to fund the huge backlog of road repairs.”
A spokesperson for the Convention of Scottish Local Authorities, said: “All of Scotland’s councils are committed to delivering essential services to their communities. The fact is roads are competing with the wide range of other services councils provide.”
The Scottish Government said trunk road maintenance had increased by £33 million this year.
Its spokesperson said: “We are making significant efforts to maximise every penny that is spent.”