Qualifying commences at 11 AM ET (4 PM BST) on Saturday 18 May. Each car is given a single, four-lap run to set an average speed – and goes in an order selected by random draw on Friday night (listed at the bottom of this story).

When every car in the qualifying order for Saturday has had at least one chance to qualify, teams may choose from two lanes at the end of the pits for subsequent attempts.

Cars in the Priority Lane (Lane 1) must withdraw their qualified time but get priority access to the track ahead of Lane 2. That second lane is for cars that have already qualified and want to try to improve their position but choose not to risk forfeiting the speed average they have already set.

The fastest 12 drivers will progress to contest the front four rows of three. The four drivers who will squabble over the three slots on the last row will also have been defined.

On Sunday 19 May, from midday (5 PM BST) the dozen drivers still in the fight for pole will get a one-hour practice session, and this will be immediately followed by an hour’s practice for the desperate quartet due to battle over the last row.

Sunday’s Indy 500 Qualifying Format

From 3:05 PM local time (8:05 PM BST) comes Top 12 qualifying, in which positions 7 – 12 will be determined.

Their running order is based on Saturday times, slowest to fastest, and each car is guaranteed one attempt. The quickest of the six then advance to the Firestone Fast Six shootout.

At 4:15 PM local time (9:15 PM BST), the four Last Chance Qualifiers will compete for positions 31 – 33 – there are 34 entries for this year’s race, so someone is going home on Sunday night.

The car’s most recent qualification speed will remain eligible for the starting line-up until the time is withdrawn or qualifications end.

At 5:25 PM local time (10:25 PM BST) comes the Firestone Fast Six shootout for pole position in the 108th running of ‘The Greatest Spectacle in Racing’.

Positions 1 – 6 will be determined, and the running order is based on times from the top 12 qualifying, slowest to fastest. Each car is guaranteed one attempt.

The top 12 drivers on the starting grid will receive IndyCar Series points, with the pole winner earning 12, the second fastest 11, down to one point for the 12th-placed starter.

Originall written by Charles Bradley for Autosport.