It's in an effort to promote more side-by-side racing.

Nick Laham

The traction "agent" is called PJ1, and will be applied to the track before the races this weekend. PJ1 will be put on both turns.

According to Speed51.com:

“With the intent of creating another groove for the drivers to produce more exciting on-track racing for our fans, New Hampshire Motor Speedway will be applying a PJ1 compound to all four turns of the 1.058-mile speedway prior to any on-track racing for the July 14-16 NASCAR race weekend,” said David McGrath, the Executive Vice President and General Manager of New Hampshire Motor Speedway in a statement to Speed51.com powered by JEGS.

The exact location in the turns where the substance will be applied hasn't been made public knowledge.

It's all in an effort to make the racing more exciting for the drivers and fans!