Although most large Texas jurisdictions and many smaller communities have opted to close their jails and lockups in favor of "direct booking" into the county jail system, the Houston Police Department continues to operate a jail system independent of the Harris County Jail. Fifty-five percent of Houston's jail population have violated municipal ordinances such as traffic offenses (except the county offense of drunk driving), public intoxication, and health code infractions. The average length of stay is 3.5 days. Each of the 5 police substations has a small holding area of 4 to 8 cells with a prisoner capacity of 15 to 30. Prisoners are held here until they can be transferred to a major jail complex. In January 1988, the first command station was opened to serve the concept of neighborhood oriented policing. It has a 97 bed jail and is designed to be semiautonomous from the central complex. A second command station is currently under construction. The decision to maintain a municipal jail system involves geographical logistics, political and legal restrictions, and space available for municipal offenders at the county jail.