There will be a competition caution every 20 minutes during NASCAR Camping World Truck Series races this year.
A 20-minute Caution Clock will be utilised in each event, except for Eldora Speedway, set and then triggered at the start of each green-flag run.
When the clock counts down to zero, a caution flag then will be displayed, and no 'lucky dog' free passes for lapped drivers will be awarded.
A caution occurring before the 20 minutes elapses will reset the clock, with regular beneficiary rules for the first driver one lap down applying.
The caution clock will be turned off with 20 laps remaining, with other than at Canadian Tire Motorsport Park and Pocono Raceway, where the clock will be turned off with 10 laps remaining.
NEW FORMAT FOR FOUR XFINITY RACES
In the second-tier Xfinity Seres, events at Bristol, Richmond, Dover and Indianapolis will now be comprised of two heats and one final race, dubbed the Dash 4 Cash.
Qualifying for each event will set the 40-car field and the starting positions for the two Heats with the fastest qualifier awarded the regular pole award.
Odd-numbered qualifiers will start the first heat in that order, with even-numbered qualifiers in the second.
The results of each heat will set the starting positions for the main race, with the top two Xfinity regulars in each heat becoming eligible for the Dash 4 Cash bonus.
The highest-finishing driver of those four will then be awarded the $100,000 bonus, and if a driver wins two of the four bonuses, they will all-but-secure a place in the series' new-for-2016 Chase.
"These innovations contain the elements of racing that our fans want the most," NASCAR's chief racing development officer Steve O'Donnell said.
"The enhancements put a premium on in-race strategy, and will create an unprecedented level of excitement as teams make tactical decisions that could impact their spot in the Chase."