With no signal lights or stop signs, a bicyclist can easily travel four or more miles and still beat the light rail in the median with today's 10-20 minute headways. In contrast, light rail transit would suffer. It is a big disadvantage because the expensive grade separation had to be paid out of the limited transit funds. Expensive elevators, escalators, and pedestrian ramps had to be built from transit funds. The freeway wouldn't even help traffic congestion, except for a temporary short term.
Freeways increase automobile trips and increases the average automobile trip length.
As with computer memory, usage increases to take advantage of any increase in capacity. Congestion returns as before. With more automobiles trips and an increase in miles traveled per average trip, air quality will go down. 87, enacted in 1985 by a now-defunct entity. Time is important.