If you're in a rush to get somewhere, then DART Rail is not your best choice for the next day or two.

According to a release, Dallas Area Rapid Transit (DART) is implementing speed restrictions on its light rail service between 2- 9 pm, through Wednesday, July 20.

Light rail vehicles will operate at no more than 30 miles per hour during this time. DART light rail passengers should expect delays of 10-15 minutes due to these speed restrictions.

The slowdown is due to the record high temperatures across North Texas, which are expected to last for the next several days according to the National Weather Service.

When many miles of rail are subjected to intense heat, the rail becomes hot, which can cause them to increase in length, and can develop bowing known as a "sun kink" or "heat kink."

"Right now, we're registering temperatures between 145 and 150 degrees on the rail," a DART spokesperson says. "This can lead to warping of the rails and the catenary lines to sag."

When temperatures reach 100 degrees or higher, it's not uncommon for transportation agencies to reduce train speeds to no faster than 35 mph.

According to CNN, the U.S. is experiencing a dangerous heat wave that is expected to affect a large portion of the country, with more than 100 million people under excessive heat warnings or heat advisories as of July 19. One-third of the US population is under heat advisories and excessive heat warnings July 19-20, with more than 80 percent of the population (around 265 million Americans) seeing a high above 90 degrees over the next seven days.

The above-average heat is expected to continue into at least Sunday, with every day reaching the triple-digit mark.

DART will continue to monitor the weather conditions across the North Texas area for the safety of our passengers and employees, and to determine if future speed restrictions will be necessary.

Riders can stay informed about service changes by registering for DART Alerts at www.dart.org, or by contacting DART Customer Information at (214) 979-1111.