The first practice session for the IZOD IndyCar Series' Baltimore GP was brought to an early end due to safety concerns over bumps on the track.

Several drivers were launched completely airborne when they tried to navigate a bump just before the railway line that crosses the start/finish straight, prompting the series to end the session 25 minutes early to discuss possible solutions with the drivers.

A chicane that was located at the affected area of the circuit last year was removed for this year's race. However, after initially announcing that a temporary chicane would be installed in time for the second practice session, it has opted to grind a section of the Pratt Street main straightaway to remove lip in the pavement. The work was scheduled to be completed in time for the 2:45 p.m. ET session on the 2.04-mile, 12-turn street circuit under the direction of Tony Cotman, president of NZR Consulting, whose company has overseen the track build.

"We had talked about a temporary (tire barrier) chicane and something more permanent as a solution, but those have been put aside if this grinding program works," IZOD IndyCar Series Race Director Beaux Barfield said.

Removal of the chicane, widening of the right-hand Turn 1 and reshaping Turns 5-6 (also pit entrance) were alterations to the circuit under the supervision of Tony Cotman of NZR Consulting.

“Last year, I know there were some unofficial tests performed (on the front straight)," Barfield said. "When drivers had some clear laps, they sent them straight through the (Pratt Street) chicane. The feedback from the few drivers who tried that was we should come back without the chicane. That's what happened, and immediately after letting cars on track (today), we saw that it wasn't doable.

"It's a shame because based on the feedback we got last year, and the effort the promoter has made, it was the right direction to go."

Marco Andretti was fastest at the time the session was ended with a best lap of 1m21.3343s, leaving him 0.3 second clear of Rubens Barrichello.

Pos  Driver               Team/Car                   Time        Gap
 1.  Marco Andretti       Andretti Dallara-Chevy     1m21.0211s
 2.  Rubens Barrichello   KV Dallara-Chevy           1m21.4021s  + 0.3810s
 3.  James Hinchcliffe    Andretti Dallara-Chevy     1m21.7899s  + 0.7688s
 4.  EJ Viso              KV Dallara-Chevy           1m22.0750s  + 1.0539s
 5.  Simona de Silvestro  HVM Dallara-Lotus          1m22.1513s  + 1.1302s
 6.  Tony Kanaan          KV Dallara-Chevy           1m22.2887s  + 1.2676s
 7.  Helio Castroneves    Penske Dallara-Chevy       1m22.5067s  + 1.4856s
 8.  Will Power           Penske Dallara-Chevy       1m22.5865s  + 1.5654s
 9.  Justin Wilson        Coyne Dallara-Honda        1m22.7523s  + 1.7312s
10.  JR Hildebrand        Panther Dallara-Chevy      1m22.8168s  + 1.7957s
11.  James Jakes          Coyne Dallara-Honda        1m22.9510s  + 1.9299s
12.  Dario Franchitti     Ganassi Dallara-Honda      1m23.0164s  + 1.9953s
13.  Takuma Sato          Rahal Dallara-Honda        1m23.0918s  + 2.0707s
14.  Oriol Servia         Panther/DRR Dallara-Chevy  1m23.1186s  + 2.0975s
15.  Simon Pagenaud       Schmidt Dallara-Honda      1m24.2342s  + 3.2131s
16.  Ryan Briscoe         Penske Dallara-Chevy       1m24.3858s  + 3.3647s
17.  Mike Conway          Foyt Dallara-Honda         1m24.7700s  + 3.7489s
18.  Ed Carpenter         Carpenter Dallara-Chevy    1m25.3753s  + 4.3542s
19.  Bruno Junqueira      Fisher Dallara-Honda       1m27.3063s  + 6.2852s
20.  Scott Dixon          Ganassi Dallara-Honda
21.  Graham Rahal         Ganassi Dallara-Honda
22.  Alex Tagliani        Herta Dallara-Honda
23.  Ryan Hunter-Reay     Andretti Dallara-Chevy
24.  Charlie Kimball      Ganassi Dallara-Honda