Most people back the HS2 high-speed rail project but few think the #33 billion scheme will be completed on time and within budget, according to a survey.
As many as 52% are in favour of HS2, the first phase of which, between London and Birmingham, is scheduled to be ready by 2026.
Only 18% are against it and 30% are uncertain, the survey of 1,599 adults conducted by market research firm Consumer Intelligence found.
The second phase, from Birmingham to the North of England, is due to be ready by around 2032/33.
The poll found that just 8% believe HS2 will be completed within its proposed budget and only 11% reckon it will be finished on schedule.
When asked whether the budgeted expenditure was a worthwhile use of public money, there was less support, with 42% saying no and 40% saying yes.
Asked which projects could best boost the economy, just 9% of those polled said the HS2 project could do this, the same percentage given to broadband and buses.
A total of 31% cited expenditure on roads as most likely to have a beneficial effect, followed by spending on existing railway lines (27%) and airports (14%).
However, as many as 53% said they thought that HS2 would ultimately benefit the economy.
Among those who reckoned they would use HS2 once it was finished, the price of tickets was the most important aspect for 67% of would-be travellers.
The project will drastically cut intercity journey times, but speed was only cited by 24% of respondents as the most important factor.
Just 10% would be mostly concerned about the proximity of a station in their decision as to whether to use the high-speed line or not.
David Black, of Consumer Intelligence, said: "While the HS2 project enjoys support from 52% of the public, there is very little confidence that it will be finished either on time or on budget.
"Given that the main reason for the project is to enable faster journeys, it is alarming that far more of those that are intending to use it will primarily decide to do so based on the ticket price rather than the speed of the journey.
"There is also some work to do in convincing the public that this is the best use of Government spending."