Road signs with place names in English and Gaelic do not raise the chances of drivers having an accident, a new report has concluded.
Transport Scotland commissioned consultants TRL to review what effect bilingual signs may have on drivers.
In 2009, a government minister said there was anecdotal evidence of motorists performing u-turns on the carriageway after misreading the signs.
TRL said the signs may demand more attention, but did not increase risks.
Bilingual signs were installed on selected trunk roads in Scotland following a feasibility study in 2002.
The TRL study commissioned in 2009 was the first examination of what impact the signs may have on driver behaviour and accident rates.
In the newly published document, the consultants said: "The report suggests that while there is reasonable evidence to infer bilingual signs increase the demand of the driving task, drivers appear able to absorb this extra demand, or negate it by slowing down, which ultimately results in no detectable change in accident rates.
The report later added: "Analysis of accident data in Scotland concurred with this conclusion, finding no evidence that accidents increased or decreased as a result of bilingual sign installation."
Three years ago, then transport minister Stewart Stevenson said the impact of the road signs on motorists had to be reviewed first before any more were erected.
He was responding to a call from Highland Council for more English-Gaelic signage on trunk roads.
Mr Stevenson said there was anecdotal evidence of motorists performing u-turns on the carriageway after misreading the signs.
Highland Council's Gaelic committee had written to the minister asking that the review should not be seen as a barrier to the expansion of bilingual signage.
Road signs in both Gaelic and English had been requested by the local authority on key routes to and from the region.
It asked the Scottish government to give "urgent consideration" to signage on the A9 from Perth northwards.
Also on the A96 just east of Inverness and on the A82 through the centre of Inverness to the Kessock roundabout.