Even though Santiago is considered a regional city, it is still a large enough city for visitors to justify hiring taxis whenever possible (this applies to those who are not renting their own vehicle).  The best approach would be to hire a driver affiliated with a business class hotel, such as the Gran Almirante, Hotel Centro Plaza or the Hotel Matum (since they are usually drivers conducting that business for a number of years, and personal safety is not an issue with them).  Before using a taxi, one must advise the driver where he/she is going and negotiate the rate before getting into the taxi, in order to avoid being overcharged.