Almost half of firms believe the UK's infrastructure has improved over the past five years, but only a quarter think it will pick up in the next five, according to the 2016 CBI/AECOM Infrastructure Survey.
Two-thirds (64%) suspect it will hamper the country's international competitiveness in the coming decades.
Delivery of key projects already in the pipeline is the top priority among the 728 firms surveyed. Delivery of £38bn of investment in the rail network through Control Period 5 and £15bn of investment in motorways and A-roads through the Road Investment Strategy ranked highly, along with delivery of a new runway in the South East and HS2.
Forty-two per cent of firms saw the policies undertaken since the start of the 2015 parliament -like the creation of Transport for the North - as positive steps.
However, confidence that overall infrastructure will improve in the coming five years has fallen 16 percentage points since the 2015 survey to 27 per cent).
A significant majority of firms are not optimistic that infrastructure in aviation (74 per cent), energy (73 per cent) and roads (69 per cent) will improve, with only digital bucking the trend - 59 per cent of companies expect improvements in this area.
Moreover, the majority (64 per cent) of firms feel the UK is unlikely to be more internationally competitive in 2050 than it is now, and 46 per cent are dissatisfied with the current state of their local infrastructure.
Carolyn Fairbairn, CBI director-general, said: "Infrastructure is a key driver of productivity and living standards. Day in, day out, Britain's businesses rely on our roads, railways and runways to move their goods, services and people up and down the country. Firms give the Government a good report card on infrastructure, and are pleased with its commitment in recent years to put infrastructure at the heart of its long-term economic agenda.
"But announcements and commitments are one thing. Seeing tarmac, tracks and super-fast internet cables being laid is another. It isn't right that nearly one in two firms are dissatisfied with their region's infrastructure or that confidence in the future is running low, especially when it comes to delivery, the key piece of the infrastructure puzzle.
"If we don't get spades in the ground on existing plans, it's clear we could put a major dent in the competitiveness of British business - and the UK itself. This is something we cannot afford to do, especially during this period of uncertainty as the UK leaves the EU. Firms are ready and willing to work with the Government to develop the skills and capacity to deliver on plans."