A rare moment, capturing a classic style vehicle (probably used in events and for tourism) in the middle of the city and crossing with a modern public transport vehicle.
I translate the sentence that can be read in the larger vehicle, " I walk at all gas ".
An allusion to the fuel used, natural gas, which pollutes very little compared to diesel. In Lisbon there are also buses that use BIODIESEL as fuel, obtained from the recovery of used cooking oil.