Puerto Vallarta is a large city and they have a great transportation system in place. Buses and cabs can get you anywhere easily. Most locals speak English thanks to Puerto Vallartas long standing tourist economy. The yellow cabs are cheaper than the white cabs, probably because they are not maintained as well and falling apart. Cabbies drive fast due to their deadlines so a Mario cart like experience during your side street travel will surely add adrenalin to the adventure.