Ryan Hunter-Reay set the pace in a muted first IndyCar practice session at Barber, where running time was limited by a succession of red flags.
The Andretti driver went to the top with a best lap of 1m08.8470s, but the constant stoppages prevented many drivers from gaining any meaningful track time.
Graham Rahal was the first to draw a red when he spun off the circuit early on, and while he was able to rejoin the track unassisted, the series took advantage of the stoppage to make small modifications to some track markers.
The session had barely restarted when early pacesetter Sebastien Bourdais spun into the gravel at Turn 9, prompting another stoppage.
There were 14 minutes remaining on the clock when the cars were allowed to exit the pitlane and at that point Scott Dixon, Justin Wilson and all three of the Penske entries were still yet to post a time.
Dixon's opportunity to do so was thwarted when his car stopped on the track with an electrical problem, prompting a third and final spell under reds.
The green flag was finally waved with less than a minute of the schedule time remaining, although race control extended the session to allow all drivers a final flying lap.
Not surprisingly, there was no change to the times in the final run, leaving Josef Newgarden as the closest challenger to Hunter-Reay with a lap 0.0866 seconds down on the 2012 champion's.
Helio Castroneves, Marco Andretti and Juan Pablo Montoya completed the top five.
Pos Driver Team/Engine Time Gap
1. Ryan Hunter-Reay Andretti/Honda 1m08.8470s
2. Josef Newgarden Fisher/Honda 1m08.9336s +0.0866s
3. Helio Castroneves Penske/Chevy 1m09.0094s +0.1624s
4. Marco Andretti Andretti/Honda 1m09.0930s +0.2460s
5. Juan Pablo Montoya Penske/Chevy 1m09.1395s +0.2925s
6. James Hinchcliffe Andretti/Honda 1m09.2391s +0.3921s
7. Justin Wilson Coyne/Honda 1m09.2906s +0.4436s
8. Sebastien Bourdais KV/Chevy 1m09.4433s +0.5963s
9. Ryan Briscoe Ganassi/Chevy 1m09.4521s +0.6051s
10. Simon Pagenaud Schmidt/Honda 1m09.4654s +0.6184s
11. Mike Conway Carpenter/Chevy 1m09.4978s +0.6508s
12. Will Power Penske/Chevy 1m09.5044s +0.6574s
13. Sebastian Saavedra KV/Chevy 1m09.5383s +0.6913s
14. Carlos Munoz Andretti/Honda 1m09.7400s +0.8930s
15. Graham Rahal Rahal/Honda 1m09.7860s +0.9390s
16. Jack Hawksworth Herta/Honda 1m09.8718s +1.0248s
17. Tony Kanaan Ganassi/Chevy 1m10.0126s +1.1656s
18. Charlie Kimball Ganassi/Chevy 1m10.0486s +1.2016s
19. Oriol Servia Rahal/Honda 1m10.0508s +1.2038s
20. Takuma Sato Foyt/Honda 1m10.1867s +1.3397s
21. Mikhail Aleshin Schmidt/Honda 1m10.2171s +1.3701s
22. Carlos Huertas Coyne/Honda 1m10.7585s +1.9115s
23. Scott Dixon Ganassi/Chevy