built according to the street classification system. These effectively help define neighborhoods. Development in accordance with the street classification system maintains the quality of life of city neighborhoods and improves efficiency of the road system. The classification system discourages rat running through local neighborhood streets. Transportation hubs, such as business zones and transit stations, such as Park and Ride facilities, provide focal points for districts of neighborhoods the same way trolley stops defined neighborhoods before cars. Designated Historic Districts The Department of Neighborhoods designates a number of Historic Districts, which have a similar status to Seattle Landmarks. these are: Ballard Avenue Landmark District Columbia City Landmark District Fort Lawton Landmark District Harvard-Belmont Landmark District International Special Review District Pike Place Market Historical District Pioneer Square Preservation District Sand Point Naval Air Station Landmark District Source of list: List of districts and neighborhoods Despite complications in Seattle's system of neighborhoods and districts, the names and boundaries in the following list are generally accepted and widely used. They are based on the Seattle City Clerk's Neighborhood Map Atlas, which in turn is based on a variety of sources, including a 1980 neighborhood map produced by the now-defunct Department of Community Development, Seattle Public Library indexes, a 1984-1986 "Neighborhood Profiles" feature series in the Seattle Post-Intelligencer, numerous park, land use and transportation planning studies, as well as records in the Seattle Municipal Archives. The following table is largely based on maps from the Seattle City Clerk's Neighborhood Atlas, but also includes designations from other sources. Annexations Seattle annexed eight municipalities between 1905 and 1910, nearly doubling the area size of the city. Annexations by law were begun by the annexee and had to be approved by the Seattle City Council. The appeal of the inexpensive and accessible electric power and water system services of the public utilities were the primary motivations for the annexation movements. Ballard was its own incorporated town for 17 years, annexed as its own ward. West Seattle incorporated in 1902, then annexed Spring Hill, Riverside, Alki Point, and Youngstown districts. It was the largest of the incorporated towns to be annexed. Southeast Seattle merged the towns of Hillman City and York with other Rainier Valley neighborhoods, then incorporated for the only reason of being annexed. Similarly, the town of South Seattle consisted of mostly industrial Duwamish Valley neighborhoods (except Georgetown); one enclave adjacent to Georgetown omitted at this time