One common way that sheriffs have met this challenge is through mutual aid pacts with other area law enforcement agencies. Santa Fe County (New Mexico), for example, relies extensively on officers from the New Mexico State Police, bordering sheriff's offices, and several local tribal police forces. Cross commissioning has enabled less busy officers to provide backup to the call-driven deputies of Santa Fe County. Another approach is the extensive use of volunteer and part-time reserve-type officers. Reserve deputies are often called at home and are able to respond quicker to a nearby scene than an on-duty deputy located, more often than not, at the other end of the county. The implementation of take-home car programs has gone a long way toward lowering costs, increasing law enforcement visibility, and expediting response. Communications over long distance and rough terrain have been another problem. This involves investments in computer-aided dispatch systems and powerful trunk radio systems that can eliminate dead spots in mountainous jurisdictions. Funding is often a problem, but some fast-growing counties have recognized the need for greater investment in policing, and the Federal COPS FAST grants have had a positive impact for some sheriff's offices.