A police car patrols the streets of San Diego. Its occupants are Ed Robles, a Second World War veteran, and former Vietnam War pilot Dick Engel.

They are members of the Retired Senior Volunteer Patrol, or RSVP. The unit was started in 1997 when police asked for volunteers over the age of 50 to help check on the elderly in their homes and monitor the empty houses of people away on holiday.

San Diego Retired Senior Volunteer
Dick Engel calls into police dispatch as he and partner Ed Robles respond to an accident Mike Blake/Reuters

The success of the programme led to the San Diego Police Department's traffic division requesting a unit of their own to help with traffic at the scene of accidents and parking complaints.

Over time the retired volunteers have become an asset to the regular officers of the San Diego Police Department, coming to the aid of people whose vehicles have broken down or been involved in an accident. They help to lighten the load for regular officers.

San Diego Retired Senior Volunteer
Henry Miller drives on patrol with partner Steve Rubin as they search for a vehicle involved in a hit and run accident in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Retired Senior Volunteer Patrol member Henry Miller works at an accident scene during his evening patrol in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Retired Senior Volunteer Patrol member Henry Miller is assisted by San Diego Police officer Joe Hilton after Miller found a stolen vehicle on his night patrol with partner Steve Rubin Mike Blake/Reuters

The unit has 48 volunteers, including six women, forming unarmed patrols in all-white police cars complete with sirens, flashing lights, computers systems and police radios.

They run patrols from 6am until midnight responding to traffic accidents and fires, using computerised licence-plate readers to locate missing vehicles.

San Diego Retired Senior Volunteer
Retired Senior Volunteer Patrol members (L-R) John Marshall, Ken Michael and Dick Engel attend a meeting at San Diego Police traffic division headquarters Mike Blake/Reuters

The volunteers are thrilled to be back doing something useful and at the same time, they concede, a little bit exciting.

"I thought retirement would be sitting on my butt watching TV," said Steve Rubin, who retired as a paramedic in Los Angeles in 2008. "That worked for about a month and then I came over to RSVP because I needed something to do. I thought it would be interesting and I could do something for the community.

"I'm happy to get out there and do my thing and at the same time release a police officer to do real police work."

San Diego Retired Senior Volunteer
Steve Rubin and Henry Miller grab a late meal at a restaurant while out on patrol in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Steve Rubin, Henry Miller and Robert Stewart talk with a San Diego Police officer as a vehicle is towed away from an accident scene Mike Blake/Reuters

Mike Blake, the Reuters photojournalist who accompanied the RSVP crew, said he was told several times that their wives were happy to see their husbands stay active and get involved in the community. Having their menfolk out from under their feet was an added bonus.

"I love it," said 88-year-old Robles, who retired from teaching in Long Island in 1991, then moved to San Diego. He's been a volunteer for about 16 years, and first got involved with RSVP five years after he stopped paid work. He sees himself carrying on with the patrols as long as his health allows. "I don't know when I'll retire from it."

San Diego Retired Senior Volunteer
Ed Robles marks a car's position on the road while answering a parking complaint in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Ed Robles explains parking regulations to the roommate of a truck owner, while on patrol in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Ed Robles, an 88-year-old Retired Senior Volunteer Patrol member, plays racquet ball at a 24-hour fitness centre in San Diego Mike Blake/Reuters
San Diego Retired Senior Volunteer
Ed Robles chats to Larry Tyson and Luke Meadows as he works out at a 24-hour gym in San Diego Mike Blake/Reuters