If you rent a car , you'll make the most efficient use of your time. While you may get a cheaper deal from a local rental company, national chains such as Avis (tel 800/874-3556), Hertz (tel 800/654-3131) and Budget (tel 800/468-5822) are very likely to be more reliable, and offer 24-hour emergency service. Weekly rates for an economy car in San Juan start at around US$280. AAA (tel 800/222-4357 or 787/764-4913) also operates emergency roadside assistance for members. Driver's licences from the UK, US, Canada, Australia and New Zealand are valid for up to three months.

Highways are fast and fairly well maintained. As in the US, motorists drive on the right side and speed limits are posted in miles per hour. Unlike the US, distances are posted in kilometres and road signs are in Spanish. In the cities, be aware that drivers are often reckless and impatient.

While Puerto Rico is without islandwide bus or rail transportation from city to city, públicos are an inexpensive, if less than efficient, way to traverse the island. Part-bus, part-taxi, these vehicles transport up to ten people over somewhat flexible routes and distances Monday to Saturday. A trip from San Juan to Ponce costs about US$10 one-way, US$20 round-trip. Each city has its own terminal; most don't have phone numbers, however, so you have to go there in person to ask about schedules.

In San Juan, the terminal is in Rio Piedras. You can also call the público line and ask them to pick you up at your hotel, but expect to pay an additional US$3 or US$4. Don't be surprised if you have to wait at least an hour, at either the terminal or your hotel. While públicos are inexpensive, they make frequent stops, so travel over great distances can be extremely slow.