The Queensferry Crossing project delivered value for money and was well managed according to a new report from public spending watchdog Audit Scotland.
But Transport Scotland needs a clearer plan to measure its wider benefits.
The £1.34 billion project, which opened last August, came in at least £110 million under budget, although its opening was delayed by eight months.
Auditor General Caroline Gardner said: “There is much the public sector can learn from the way Transport Scotland managed the project and it’s important that the good practice is shared more widely.
“The management of the project delivered value for money and achieved its overall aim of maintaining a reliable road link between Fife and the Lothians.”
Her report praised Transport Scotland’s budgeting, governance, quality assurance and risk management as was the competitive tendering process.
A key factor behind its success was the blend of skills and experience in the delivery team which had strong and consistent leadership and good communications.
But, she added: “It is too early for some of the project’s wider benefits – such as improving public transport across the Forth, cutting journey times, and boosting economic growth – to be demonstrated.
“More detail is needed on how success will be measured.
“Transport Scotland now needs to produce a clearer plan about how it will measure the success of the project’s wider benefits, including its contribution to economic growth and improved public transport links.”
It should include a plan, with timescales and actions, of how public transport firms will be supported to meet increasing demand for travel across the Forth.
Transport minister Michael Matheson welcomed the findings and set out what will happen next.
“While it is too early to complete a wide ranging assessment evaluating the project’s outcomes, we accept the recommendations in the report and aim to carry out a full post-project evaluation in late 2018 detailing performance relating to journey times and traffic flows.
“This will include an assessment of the impact of improved network connections and junctions, and the project’s contribution to economic growth and exploring what further support can be offered to public transport providers to meet any future increase in demand for travel across the Forth.”
He added: “The report provides welcome recognition of the project having delivered its objective of providing a more reliable road link between the Lothians and Fife.”
Since opening at the end of last August there have been 14 occasions on which the Forth Road Bridge would have closed to high sided vehicles due to weather conditions.
Meanwhile, he said hard shoulders were helping mitigate against the impact of accidents and breakdowns and the most recent data showed a steady overall improvements in journey times.
