Question

Do a free-hand drawing, using single lines for ramps,for the type of interchange you would recommend for each of the following scenarios:

A.A freeway crossing an urban street,with a desire to use a Diamond but not to disrupt the through traffic on the arterial with at-grade intersections.

B.Two US Primary highways crossing in a rural area. Dedicated ramps desired for each turning movement.

C.Same as scenario B, except the NE and SW quadrants are not to be used. However, at grade intersections are allowed on the N-S road.

D.An urban arterial ending at a freeway(T-intersection) with the heavier movement being from the freeway to the arterial.

Answer 1

For A - I only propose one directional ramps - 4 one directional ramps. You cannot turn left at any of the ramp directions. Lefts completely not allowed at any ramp junctions.

For B - I propose a clover leaft interchange for hook on ramps, plus the right turn ramps

For C - I propose the following like a half trumpet interchange, where in I dont use the NE and SW quadrants.

For N-S highway, they can access E-W highway at points 1 and 2. These intersections allow lefts from the ramp to the E-W

For E-S highway, you have to provide a trumpet like shap interchange where for example WB vehicles exit the road and then reach at grade junction 3 and can take lefts or right

For Question D) provide a loop on ramp for WB vehicles on the freeway to access arterial c-d southbound.