Phoenix, Arizona. — The intense heat wave enveloping much of the country is snarling transportation in some areas by causing metal railroad rails and asphalt roads to expand and buckle.

Arizona-based GS&M Transportation Co. Railroad says the heat has forced it to slow its trains in heat-affected areas by 10 to 20 mph. Company spokesman Gabe Graza said Wednesday that extreme heat can cause metal rails to expand and kink at weak spots.

The triple-digit temperatures have had a similar effect on some asphalt roads, bridges and sidewalks.

Authorities in Arizona say the heat caused a section of highway to bend, Smashing car frames and sending them to the repair shop.

In Arizona, the heat has caused dozens of roads to buckle and has damaged runways at airports in Phoenix, Mesa & Chandler.