$4$Problem $4($Problem $7-27.$ from the textbook$)$:

A two$-$lane road crosses an at$-$grade railroad track at $90.$ If the design speed

of the two$-$lane road is $45m\frac{i}{h}r$ and the velocity of the train when crossing

the highway is $80m\frac{i}{h}r,$ determine the sight distance leg along the railroad

tracks to permit a vehicle traveling at the design speed to safely cross the

tracks when a train is observed at a distance equal to the sight distance leg.

Read Chapter $7$ from the textbook. Submit solutions to these problems as a

single PDF file attached to Assignment $7$ in your Canvas account for this

course.