To alleviate road congestion, expand roads, provide alternatives or both?

In my last post I was pretty direct by suggesting, in effect, that American roadway infrastructure was heading in the wrong direction.

As you know, roadways can only handle so many vehicles per given unit of time operating at a per given unit of speed. The proper term is “capacity.” Too little capacity and traffic flow becomes affected as in road conditions getting hamstrung. Too much capacity results in underutilization. So, is finding the correct balance essential?

To give a relevant example, in California’s central San Joaquin Valley there are two main north-south highway corridors – Interstate 5 and California State Route 99, the latter route currently receiving an upgrade, it being widened from two lanes in each direction to three on many parts in Tulare, Fresno and Madera counties.

“The $68 million project, from Grantland Avenue in Fresno County to Avenue 7 in Madera County, is part of a long-term plan to widen Highway 99 to at least six lanes from Kern County to Sacramento, said Caltrans spokesman Jose Camarena,” The Fresno Bee columnist Eddie Jimenez wrote.

“How long it will take to reach that goal is unknown, he said. Caltrans [California Department of Transportation] projects are approved as funding becomes available.”

Aside from this, interest has been building as of late regarding the extension of a third – State Route 65 – as a way to take some of the load or pressure off of the other two. The proposed extended portion would tack on from where the road currently terminates on its north end, that being near Visalia (Tulare County), to at least Fresno if not farther north, perhaps to northern Madera County. But, with the widening of 99, is building the SR 65 extension even necessary?

Most certainly, construction of the SR 65 extension would bring extra capacity – this is a given. But, that “extra” pavement space? Seriously?!

Now add in one more factor. With the building of the planned statewide high-speed train corridor slated to begin this summer – the initial construction segment (ICS) to be roughly 130 miles linking Madera and Kern counties and to conclude by 2017, which, in effect, will run parallel to the Highway 99 corridor between those same two counties – some might argue the highway 99 widening is even unnecessary. Moreover, if there are portions of SR 99 plagued with congestion already, expanding concrete in those areas could possibly invite and encourage more traffic thereby further adding to the congestion problem.

People-moving-logistics specifics

One lane of a two-lane freeway (one lane devoted per direction) might handle adequately 2,400 motor vehicles per hour each traveling at 60 miles per hour. Twenty-four hundred motor vehicles traversing a section of highway in an hour would affect at least 2,400 people. Added to each vehicle could be extra passengers. But capacity here is 2,400. That same capacity could be accommodated by eight high-speed passenger trains each carrying 300 passengers in that same hour on one track. Eight trains spread evenly over an hour’s time means a train every 7.5 minutes. This is a reasonable frequency for a high-speed passenger train operation. But what if traffic volume were to increase to say 3,200 vehicles per hour (a 33 percent increase), this would mean the addition of an added 800 vehicles per hour in which case highway traveling speed would no doubt be compromised.

On the other hand, that same 800 could potentially be absorbed quite comfortably by high-speed trains without necessarily having to add more trains and without speed being compromised, although an extra passenger car or two per train would likely be required if others are already at full capacity.

So, in the highway scenario where more vehicles per given section of highway would be added, accommodating the same increase in passenger volume via train might only require adding more passenger handling capacity per train. Whereas additional concrete could be the prescribed resolution with which to effectively handle the increased traffic demand on the highway, in the railroad scenario an extra passenger car or two per train would be required. This is another way of saying that trains, all things being equal, yield more bang for the buck.

On top of this, unless all highway vehicles are zero-emissions capable, electrified high-speed rail provides a far more sustainable service in moving the same amount of people from point A to point B.

So, my main argument here is this: Since high-speed rail will soon be in the works, is the State Route 99 work all for naught? All things considered – the expectation being x number of people in the years ahead will make the switch to trains from cars (and aircraft) coupled with an expected population increase – at this moment in time the answer to that question is “unknown” at worst and “yes” at best.

For what it’s worth, I will go with rail any day.

– Alan Kandel