Christin Ernst was in a fix. An errant screwdriver punctured her tire on a San Diego freeway, leaving her stranded. That is when Thomas Weller - also known as the San Diego Highwayman - arrived in his monstrous white search-and-rescue vehicle, complete with emergency lights flashing. A surprised Ernst watched as Weller slapped on her spare, inflated it and handed her a card. It reads: Assisting you has been my pleasure. I ask for no payment other than for you to pass on the favor by helping someone in distress that you may encounter." She was lucky. Because of wallet-busting fuel prices, Weller has cut back his good Samaritan runs to once every three days. Weller's aging rescue rig, which weighs more than 5,600 pounds, is a world-class gas-guzzler. "I sit home on the front porch a lot," he said. "It's killing me." Weller started his volunteer highway rounds in 1966. Now 60, he figures he has helped more than 6,000 motorists. Mostly, he helps people whose vehicles are out of gas, or have a flat tires or overheated engines. For those, he carries gas, water, compressed air, and jacks capable of lifting an ambulance or a low-rider. Weller estimates the rig has gone 600,000 miles - the odometer broke 10 years ago. To make a living, he has been a roofer, car repair manager, and security guard. These days, he fixes cars for a select group of customers. He said his job provides enough money for his modest lifestyle. It also covered his daily drives - until gas prices went up.