The RET trial will run until spring 2011
A pilot scheme offering lower fares on all ferry routes to the Western Isles has increased traffic significantly, the first minister has said.
Road equivalent tariff (RET) was launched by the Scottish Government in October last year.
It bases the cost of travelling on the equivalent distance by road.
Alex Salmond said since the scheme started there had been a rise in the number of visitors, family, friends and businesses visiting the isles.
The Oban-Castlebay/Lochboisedale route has seen a 26% increase in cars and 19% more passengers, compared with the same period in 2007-08, according to government figures.
On Uig-Tarbert/Lochmaddy, cars were up 25% and passengers by 16%, while there was a 24% rise in cars and 13% in passengers on the Ullapool-Stornoway route.
The route from Oban-Coll/Tiree has had 13% more cars and 8% more passengers.
Speaking as the Scottish Cabinet was meeting in Stornoway, Mr Salmond said: "These positive, early signs, particularly the economic benefits, will continue to be closely monitored through our study of the pilot so we can fully evaluate the impacts of RET."
He added: "I can give all Scottish islanders the assurance that we remain absolutely committed to ensuring the necessary transport links at affordable prices.
"This will enable greater connections, socially, culturally and economically with mainland Scotland."
Highlands and Islands Enterprise urged businesses using the ferries to complete a survey to help the government assess the pilot.
Bill Lawson, chairman of Harris community company, Co Chomunn na Hearadh, said: "We are certainly seeing more visitors, and particularly camper vans, which has had a significant effect on sales in our shop.
"If local businesses can meet the needs of the increased number of visitors and provide the quality they are looking for there is no doubt we can take advantage of RET."
The trial will run until spring 2011.
Its launch brought complaints from Orkney, Shetland and Argyll because they were not included.
Last month saw the first Sunday ferry service run between the mainland and Lewis on the Western Isles.