Herb made his IRL debut in the first race of the 2000 season, but did not compete in any other races that year. He made his Indianapolis 500 debut in 2001, finishing 27th and competing in five other races. He raced in six more races that year, but failed to qualify for the "500" in 2002. In 2003 he moved to the Infiniti Pro Series, where he owned his own team and captured a single IPS win. He returned to the IndyCar series for the 2006 Indianapolis 500 in a Playa Del Racing Panoz, of which he was a co-owner, but yielded the car to Roger Yasukawa, who qualified it for the race.
Herb qualified in the 27th starting position for the 2007 Indianapolis 500 and finished 32nd after crashing on lap 53. He also crashed in practice earlier in the month.
He continued to run a limited schedule through the 2007 IndyCar Series season. In June 2007 he raced in the series' Texas Motor Speedway event, finished 20th after spinning entering the pits. He also entered the Michigan 400, but struggled with broken suspension problems, and finished 20th after spinning and hitting the wall. He sold his team's chassis to the league's pool of chassis for former Champ Car teams following open wheel unification prior to the 2008 IndyCar season.
|2006||Playa Del Racing||HMS||STP||JPN||IND|
| Top 10s|
| Indianapolis 500|
|2002||G-Force||Chevrolet||Failed to Qualify|
|2006||Panoz||Honda||driven by R. Yasukawa|