overhead light has been in use by the agency since 1979. The red overhead lights on some MSP cars are 25–30 years old. Vehicle testing Michigan State Police is one of only two agencies in North America (the other being the Los Angeles County Sheriff's Department) that conduct annual tests of police and special services vehicles. MSP typically conducts their top speed and braking tests each fall at Chrysler Proving Grounds in Chelsea, Michigan and vehicle dynamics and handling tests on the road course at Grattan Raceway in Grattan Township, Michigan. Tests are open to members of the law enforcement community, fleet managers, and other interested parties, and results are published for the benefit of the law enforcement community. Many of the specifications and option offerings for Chrysler, Ford, GM police vehicles are a result of findings and suggestions stemming from MSP evaluations. Annual test results are published at the MSP Website Aviation Unit The five aircraft in the Michigan State Police Aviation Unit are assigned several duties: search and rescue relays traffic enforcement traffic control security training investigative and administrative flights Mobile Command Vehicle The Michigan State Police operates one Mobile Command Vehicle as of 2006. The vehicle has an International chassis and engine and weighs . It is equipped with GPS, satellite television, a diesel electric generator, and a lavatory. The vehicle is also equipped with a variety of radio systems that allow those operating it to communicate effectively in the field. The vehicle was utilized during Hurricane Katrina relief in September 2005 and is also frequently used at large events throughout the state. Miscellaneous information The department's value statement is: A PROUD tradition of SERVICE through EXCELLENCE, INTEGRITY, and COURTESY. The department requires that the emphasized words be shown in capitalized print when the statement is reproduced in any fashion. The department's work sites are called "Posts," much as a local police department's offices are referred to as "stations." Many MSP posts are similarly designed and feature a distinctive two-story architectural style with a front door centered above exterior steps to the first level and a sandstone center section engraved with the state seal and the words "Michigan State Police". Many of these buildings were built in the 1930s in the years following The Great Depression just before World War II. To date, 53 Michigan State Police Troopers have died in the line of duty. As of