The NFL's workhorse running backs need their own version of Farm Aid.

The instances of one player handling a team's rushing load are increasingly rare. Statistics and the 2010 draft show just how antiquated the role is becoming.

"You can have a workhorse running back and give him his carries, but you can be a little more successful if you have a couple of guys," said Chicago coach Lovie Smith, whose team added ex-Minnesota RB Chester Taylor in free agency to complement starter Matt Forte. "It's a hard, grueling season. That's why we got Chester.

"We want to be able to run the football. You need two -- and preferably three -- good guys to do that."

A growing number of teams believe in Smith's philosophy. Led by Tennessee's Chris Johnson, only six running backs averaged 18-plus carries a game last season. That is the lowest total since 1992 and a drop of more than 50 percent since 13 RBs hit the mark in 2007.

A 20-plus carry average -- once a reasonable expectation for a starter -- is no longer the norm. There were four players in each of the past three seasons with such production. In comparison, an average of 11 running backs broke the 20-plus barrier between 2003 and 2007.

The main reason for the shift is an overall increase in pass attempts. In another generation, a running back as physically gifted as Minnesota's Adrian Peterson would already be on pace to become this generation's version of Earl Campbell. Peterson, though, didn't crack the 20-carry average in 2009 and wasn't overworked during his first three NFL seasons.

"I have a great affinity for the run," Vikings coach Brad Childress said. "I think at some point you have to put your hands on people and exert your will. But with that said, we are passing the ball more. You have to find different ways to utilize (Peterson). Is it always going to be 30 carries a game? I don't think so."

The greater aerial emphasis coincided with a 2004 offseason NFL decree spearheaded by Indianapolis president Bill Polian. Officials were told to more strictly enforce illegal contact calls on defensive backs, which led to looser pass defenses.

Polian's charges now embody the throw-first philosophy. The 2009 Colts became the first team to reach a Super Bowl after finishing last in rushing during the regular season.

"The rules in the league lend themselves toward passing," St. Louis coach Steve Spagnuolo said. "You're now looking for someone who can come out of the backfield and do all those type of things."

Enter C.J. Spiller.

The Clemson standout will be the first running back drafted on April 22. He may even be the only player taken at the position in the first round, something that hasn't happened since 1984.

Spiller proved he could handle a full workload during his senior season. But Spiller, like Reggie Bush in New Orleans, may be most effective when used in a situational role that takes advantage of his blazing speed without taking the pounding that comes from being the traditional between-the-tackles plugger. The 191.4 career yards Spiller averaged through rushing, receiving and special-teams returns set an NCAA record.

"Spiller is dynamite," San Diego coach Norv Turner said. "He does it all -- the return game, the explosiveness, the perimeter running. There are big plays just waiting to happen."

Turner has that kind of weapon himself in Darren Sproles. A 5-foot-6, 185-pound frame has limited Sproles' carry totals and relegated him to a backup role. But the home-run threat Sproles provides is so valued that San Diego is paying him a combined total of $13.9 million for the 2009 and 2010 seasons even though the team now needs to find a replacement for jettisoned starter LaDainian Tomlinson. Felix Jones (Dallas) and Leon Washington (New York Jets) are considered the same type of complementary big-play backs as Sproles.

"When you have running back-by-committee, you can have change-of-pace backs with different skill sets," Atlanta coach Mike Smith said. "That's important because of the defenses. You want to give them different looks rather than where they're tuning into the same style of running back and know how to attack him."

Some rushers don't want a committee situation even though it may lead to prolonged careers and less wear-and-tear. Spagnuolo admits that Rams RB Steven Jackson "doesn't want to come off the field. If he wants to be out there, you've got to keep him out there." Spagnuolo, though, says he is seeking a running back this offseason to help alleviate Jackson's heavy offensive burden.

"You have to be very cognizant of the number of carries and how much exposure you're going to give to the running back," said Smith, who ran starter Michael Turner an NFL-high 376 times in 2008. "You can get lost as a coach sometimes ... It's very hard for the running back to take the pounding when he gets to 350-plus carries."

That's something most of today's rushers won't have to worry about as the workhorse running back gets put further and further out to pasture.