Longobart's department also services its vehicles every 3,000 miles. At these maintenance intervals, technicians inspect the vehicle from bumper to bumper, including the tires. Because severe service shrinks tire life expectancies, technicians must guesstimate tire wear from interval to interval. Though a tire may appear to have another 3,000 miles left on it, technicians must downgrade its useful service life and often change it prematurely. The tire may then be used as a spare or retired because it may not last until the next service interval.
Even so, daily checks are critical. "A tire can be worn out between intervals - even if it's being used the same way between services," Longobart states. "It only takes one high speed pursuit, or an officer spinning the wheel one too many times, for it to wear out."
Putting the onus on officers to inspect tires before each shift and educating them on how driving tactics impact tire integrity also helps safeguard tire life, he adds. User groups within the Inglewood department encompass tire maintenance and vehicle operation.
These groups drive home the message that vehicle maintenance is part of an officer's responsibilities. "They don't just get in the vehicle and drive," Longobart says. "They must check the brakes, make sure there's gas, and inspect the tires for proper inflation and other problems."
Even if a department does everything right from selection to maintenance, the risk for blow outs remains. "No matter what the tire brand, as long as there are potholes in this country, no tire is going to keep us safe," says Rick Cole repeating the words of a Greyhound executive he once did business with. Cole is the chief executive officer of Tyron Automotive Group USA, a Burbank, California-based company that manufacturers blow-out protection. "This is true for law enforcement, too," he adds. "Our roads are getting older. They are cracked, have potholes and ruts. Regardless of whether a tire is high speed rated or heavy duty, there is always a chance that if you hit a pothole at high speed, the tire's going to go."
When a tire deflates, air pressure no longer holds it in its correct place on the wheel. As a result it becomes free to move about and the tire's beads can slip over and into the wheel well, causing the tire to flail or flap about. The driver loses steering control and the flapping tire may cause serious damage to the vehicle and passengers.
The Tyron wheel band attaches over the wheel well after the tire has been fitted, to support a deflated tire and prevent it from slipping into the wheel well after a blow out.
The device holds the sidewalls vertical, keeping the wheel off the ground. This increases stability after a tire fails, and in turn maintains steering, braking and cornering control.
"With Tyron in place, our officers can drive on a flat tire and get it to the garage for repair," says Longobart, who used Tyron wheel bands as maintenance superintendent for the City of El Segundo, California. "They also enhance the safety of the driver because if there is a blow out at high speeds, the tire maintains stability allowing the vehicle to come safely to a stop."
Run-flat tires also are peaking the interest of some police departments. However, to date not a single U.S. police department uses them. The main reason for their lack of popularity is expense, says Cole. Equipping a vehicle with run-flats runs upward of $1,600 for tires that offer little more than 20,000 miles. "A department the size of the Los Angeles Police Department replaces tires every 30 to 60 days," he points out. "If you quadruple or quintuple the cost of tires, you make it well beyond the reach of any department budget."
Today's run-flats also do not handle well in high speed turns or on wet pavement, making them a danger to the police fleet, he adds. They negate the spike strips often employed in high speed chases. And being directional, meaning a left tire can only go on the left side of the vehicle and vice versa, would require patrol vehicles to carry two spares in their already overcrowded vehicle trunks.
Even so, Longobart predicts as the technology improves and the price comes down, manufacturers will eventually spec run-flats on all police vehicles. The challenge is creating run-flats that perform like today's pursuit-rated tires, Alley adds. But this may happen sooner rather than later as Ford Motor Co. and General Motors Corp. conclude their work on run-flats designed with police service in mind.