If your Main Street line has a couple of points that you can find the coordinates ( x1, y1) and (x2, y2) you could determine the slope of the Main Street line : m= (y2-y1)/(x2-x1). Or maybe you can determine what the slope is from the line being a particular line , horizontal, etc. The slope of your path line would be m1 = -1/m. Use some point on this path to write the equation of a line in point- slope from. Suppose ( x3,y3) would be a point , ( look for example for the entrance coordinates), write y= m1(x-x3)+ y3 and plug in then values of m1, x3, y3 to have your path line equation. ~Nesabug :3
