Police are warning drivers in Peel to take extra care with the introduction of a new one-way system.
The major traffic changes in the west of the Isle of Man are the first phase of the Peel regeneration plans.
Christian Street is now one way from Atholl Place to Church Street, as is Derby Road, between Mona Street and Atholl Place.
Inspector Will Campbell said: "The new layout is well signed and any competent driver should be able to understand."
He said motorists should take extra care while the work is completed.
A spokesman from the Department of Highways said the plans had been drawn up after a series of public consultations over the past two years.