Commentary: Can We Fix Mace?

It was a week ago that about 200 people met at Pioneer Elementary and consultants from Fehr & Peers gave us the data which really suggests that very little that we do will fix Mace Boulevard until I-80 is fixed.

The public in attendance on Thursday of last week definitely had a single solution in mind – change Mace back to the way it was.  The problem is that as Fehr & Peers consultant Adrian Engel pointed out, fixing Mace means encouraging more cars to bypass I-80 on Tremont in Dixon – which will simple add to the congestion.

Most people at the meeting didn’t want to hear that.  They have convinced themselves that the problems began when the city redesigned Mace.  They forget that the same problems existed in the winter of 2017, well before the city did any construction on Mace.

Let’s walk through component parts of the corridor.

First of all, most of the time the corridor is relative free flowing.  The problem times are Thursday and Friday late afternoons to evenings.  That’s when the traffic on I-80 comes to a stop, and when the maximum flow of traffic – estimated at roughly 200 cars per hour bypassing I-80 in hopes of saving ten minutes (the Enterprise article suggested it was one minute of savings, and perhaps at the time they looked it was, but Mr. Engel suggested it was ten based on their analysis).

Second, let’s look at southbound Mace from Harper Junior High to the I-80 on-ramp.  To me this is the critical tell that the problem isn’t construction on Mace, but rather I-80.  Why?  There is no construction on this part of Mace.  The traffic backs up to the on-ramp and once you get past the freeway entrance there is no congestion.

Eastbound Chiles at the intersection of Mace:  There is a back up along the Chiles frontage road.  The cause of that back up – traffic that was attempting to turn left at Mace and onto the freeway.  Because of the backup on the on-ramp and the queue, that traffic backs up onto Chiles.  A few cars can turn at a time, and impatient turning vehicles will block the intersection.  The other week I saw a big rig do that and block half the intersection for a full cycle.  A police office ended up talking to the driver.  While frustrating, none of that is due to construction on Mace, as it is all well to the north of the construction.

Westbound Chiles at Mace:  There isn’t a huge amount of traffic here.  The big problem, though, is the backup from the on-ramp will block right turns for vehicles not attempting to turn onto the freeway, and there is a mild back up for vehicles that are attempting to turn onto the freeway.

Eastbound Cowell: Two weeks ago it took about 20 minutes to get from Drummond past Mace going straight, as opposed to turning onto Mace.  Last week the traffic flow was fairly clear until the immediate intersection.  The difference, apparently, was that there was a vehicle collision two weeks ago that caused a massive back up on the whole system.  Last week there was not.  The good news here is that cars have lined the left turn, lane allowing through traffic to get through.  The left turn back up is exclusively caused by back up of traffic getting on the freeway and is completely unimpacted by redesign.

Westbound Cowell: Here is the first of these components that is impacted by the redesign.  There is a backup here for traffic attempting to turn right and get on the freeway.  With the redesign, there is no longer a separate turn lane – which means that traffic wishing to continue onto westbound Cowell is caught up in the traffic attempting to turn north on Mace and onto the freeway.  It’s not a ridiculous back up, but it is causing a delay for local traffic.

Northbound Mace south of Cowell: Here is what is happening.  The single lane is preventing vehicles wishing to continue north on Mace to get caught up in the delay.  That means if you are going to Nugget or Target rather than eastbound I-80, you are stuck until you get past Cowell – at which point, you simply get into the left lane and are free and clear.

Can they fix that part of it?  The consultants are talking about restoring that area to two lanes.  But there is risk there.  Can you convince vehicles to stay in the right lane, or will there be a temptation to jump the queue, and then cut over causing the entire roadway to back up?

We can probably look at the other direction as a guide.  What we see going southbound is, if the traffic back up is moderate, through traffic can go in the left lane and largely bypass the queue.  However, once the traffic reaches a critical mass, traffic attempts to bypass the queue and then cut back over at the end, which leads to the back up in both lanes.

Our guess, therefore, is that when traffic gets bad enough, both lanes are going to be blocked and there will be no way to bypass it.

Engineers are therefore looking at a few fixes.  First, they want to add signals along the corridor to better meter and space the traffic.  Second, they do want to add back the lanes taken away.

Mr. Engel noted this will “allow some of the local traffic to bypass the queue to be able to get around some of the traffic.”

The problem again, by creating additional capacity, is “it could induce people to leave 80 at Dixon and drive into this community.”

He warned that could mean, instead of 200 cars, there could be 400 cars because I-80 hasn’t gotten better yet and there would be additional capacity on this road.

Finally he suggested adding ramp meters to the HOV (high occupancy vehicle) bypass lane at the freeway on-ramp.  Right now, he said half of the cars jump over to the HOV lane to bypass the traffic signal because they’ve been sitting on Mace for 35 minutes and calculate it is unlikely they will be caught and ticketed.

In general, while I think they can improve Mace south of Cowell a bit, most of the problems are not caused by the redesign and are instead caused by the increased volume of traffic on I-80 – and until they address that, things really aren’t going to get better.

—-David M. Greenwald reporting