Tacoma's system of transportation is based primarily on the automobile. The majority of the city has a system of gridded streets oriented in relation to A Street (one block east of Pacific Avenue) and 6th Avenue or Division Avenue, both beginning in downtown Tacoma. Within the city, and with a few exceptions, east-to-west streets are numbered and north-to-south streets are given a name or a letter. Some east-to-west streets are also given names, such as S. Center St. and N. Westgate Blvd. Streets are generally labeled "North", "South", "East", or "North East" according to their relationship with 6th Avenue or Division Avenue (west of 'Division Ave', '6th Avenue' is the lowest-numbered street, making it the dividing street between "North" and "South"), 'A Street' (which is the dividing line between "East" and "South"), or 1st Street NE (which is the dividing line between "East" and "North East"). This can lead to confusion, as most named streets intersect streets of the same number in both north and south Tacoma. For example, the intersection of South 11th Street and South Union Avenue is just ten blocks south of North 11th Street and North Union Avenue.