Motorists have endured hold-ups on the Queensferry Crossing on one day out of every three.
Figures released by the Scottish Government showed there were lane restrictions on 121 days last year. In the first half of this year there have already been 57 days of restrictions.
Delays have been caused by accidents, breakdowns, roadworks and the removal of hazardous items.
News of the regular hold-ups for people travelling to and from Fife prompted claims of mismanagement of the project.
The £1.35 billion bridge opened in August 2017 but finishing works are expected to continue to October this year.
Mid Scotland and Fife Conservative MSP Dean Lockhart said: “These figures provide proof that since it opened drivers using the Queensferry Crossing have been consistently hampered by delays and restrictions.
“The crossing is a vital link for my constituents in Fife and the least that residents living in the Kingdom could have expected is that it would help them get to their work on time but this has simply not been the case.
“The SNP’s haste and mismanagement when it comes to this project is to blame, and they have let down people across Fife.”
Lane closures have varied in length from four minutes to 17 days, some of them affecting Fife commuters travelling to and from work in Edinburgh.
There were restrictions on 26 days in May last year and on some days there may have been more than one lane closure.
Most were for maintenance works outside of peak times.
A Transport Scotland spokesman said: “Nearly 80,000 vehicles use the Queensferry Crossing each day and since opening there have been over 20 occasions when it has remained open when the Forth Road Bridge would have been closed or restricted for HGVs.
“The new crossing is delivering clear economic benefits for both industry and commuters, a fact recognised by the road haulage industry.
“As is standard on any major trunk road carrying this level of daily traffic, there has been a wide variety of reasons for lane restrictions on the Queensferry Crossing since 2018, including accidents, breakdowns, roadworks and the removal of hazardous items.”
