LOS ANGELES (CBS) — An engineering professor at the University of Southern California warned Tuesday that the city’s latest light rail line could pose a risk to students and pedestrians.

KNX 1070′s Pete Demetriou reports serious concerns are being raised about safety at a number of crossings along the the Metro Expo Line in downtown Los Angeles.

USC Professor of Engineering Najmedin Meshkati has studied the construction of the line since 2007 and is concerned over what he calls a lack of signage or safety features at intersections like Western and Denker near the Foshay Learning Center along Exposition Boulevard.

Meshkati has suggested a redesigned X-type intersection at the train crossing at Expo and Rodeo — a proposal that earned the endorsement of at least one frequent rider.

“If nothing else, a crossing guard to guide the kids and stop ‘em, ’cause kids run, you know, they be excited, they be doin’ other things, they mind is not focused on the train,” said passenger Nisha Oheny.

Metro officials have rejected calls for a redesign of the intersection, saying it would be both too expensive and unwarranted.

The warning marks the latest safety concerns to dampen commuters’ excitement over the Expo Line after state safety regulators ordered Metro to investigate reports of audible scraping sounds heard along a key stretch of the line on Washington and Flower.