Unless there is a specific left turn lane at an intersection on a two-way street with signals, left turns are prohibited. Right turns at red lights are also prohibited. Cutting a traffic circle, whether or not there is cross traffic, is an offense. Although there is currently a temporary exception for Argentine coins used by Argentine drivers, made because of the decline in tourism resulting from international access road blockages, tolls (peajes) must be paid in Uruguayan pesos. Uruguayans in cars and trucks are nearly as sane and disciplined as Chileans on major roads and in cities. Autos obey traffic signal lights. On potholed streets or rural roads the concept of lanes can get pretty fluid as drivers dodge holes (pozos) as best they can. Bicyclists and motorcyclists, however, behave as though traffic rules apply only to vehicles with four or more wheels. Many cyclists do not have or use lights at night. Some drivers believe that keeping their own lights OFF or on parking improves their night vision - so look very carefully before turning, entering onto a major highway or approaching an intersection after dark. I lived 30 km east of Montevideo for nearly three years, half driving a Peugeot, half on our two motos. Fuel brands vary but prices do not, all being set by ANCAP (Administración Nacional de Combustibles, Alcoholes y Portalnd) which also runs the largest chain of service stations. Service stations are nearly everywhere, except not many are open along the route from Colonia to Montevideo if you arrive on the Buquebus that departs Buenos Aires at 0030. Legal fuels are nafta (gasoline)and diesel ( same as Argentine gasoil or US diesel.) A number of cars, trucks and what-have-yous run on Supergas, that is compressed natural gas. Unlike Argentine instalations with secure tanks, etc, the Uruguayan versions are illegal, informal, conversions using 13 kg steel tanks, loosely mounted on inclined wooden ramps inside car trunks. Rear-ending a Uruguayhan auto an thus be a very poor move. Enjoy Uruguay.