May 26, 2021


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Here's a point you guys can use if this idea moves forward to public consultation:

West Marine Boulevard, Oak, and Pine would be screwed getting to northbound Highway 1. If you can't get to Cypress, you're not getting to Highway 1, as the roundabout backup will extend way past Marine on weekend afternoons.

Wherever the roundabout is located would become the only way to get to Highway 1 when traffic is backed up. So weekend mornings would see any eastside street north of the roundabout having to go to the roundabout via Moss Beach streets to get to southbound Highway 1.

And the reverse on a weekend afternoon -- any westside street south of the roundabout wanting to go north on Highway 1 would have to get to the roundabout on Moss Beach streets to get out.

Also, the backups on both sides of Cypress (assuming the roundabout was put there) could get bad because of that, especially in an emergency.

Completely valid point, John. Although generally the more traffic on the entering side road the better, until it overruns the main road traffic. It's when those new developments grow larger than the main arterial that the roundabout gets pulled and replaced with a flyover.

I'd also point out that the roundabout in that presentation from Kentucky is unlike anything I've ever seen, anywhere. It's so ridiculous to use as an example of roundabouts -- it's clearly been created and/or run by some agency that got confused as to how roundabouts work. It's like showing an intersection in Mumbai to convince people what would happen in Moss Beach. This is data manipulation through cherry-picking, starting with a required result and working backward. It's insulting to people's intelligence, as if to suggest that an extremely effective traffic solution used throughout the world is flawed because Kentucky screwed it up. You have to make a better argument or those experts will eat you alive. They can equally show presentations of hundreds of roundabouts that work fine.

With all of the (literally) thousands of roundabouts I've driven, I really believe that it could be made to work in Moss Beach, but that absolutely doesn't mean it would do so -- I'm sure Caltrans would be equally able to screw up a sound design. And it certainly doesn't excuse Caltrans from using equally cherry-picked data to Trojan Horse developments in to the coastside. And you can be assured it would slow and back up Highway 1 traffic through Moss Beach, a lot.

And, precisely to your point, two new mega-neighborhoods are in planning for Moss Beach: Big Wave to the south (watch Cypress Street become a worse bottleneck) and Midpen low-income to the north (watch California Street turn into a nightmare).

I can honestly say I've never seen a roundabout force circulating traffic to stop for entering traffic. Except in Italy where the rules are different (no rules at all). In NZ, Australia, and the UK they're used extensively for situations like Montara and Moss Beach.
Which again is not to comment on their appropriateness there because your point about Moss Beach currently not being a chokepoint is valid, but using a misunderstanding of how roundabouts work to pin your argument on won't help you to argue your point to your fellow coastsiders.

I think that because Americans are inexperienced with roundabouts, they consider them to be inherently flawed (there are so few here that the mere fact you're quoting roundabouts 200 and 300 miles away speaks for itself). If you drive in a country where they are used extensively, you'll find them in situations exactly like the coastside, again and again and again. Long (and I mean long -- worse than Moss Beach) queues of weekend traffic stopping locals from getting out.

The way a roundabout works is that as you circulate you're forcing all entering traffic to give way to you.

In your case, if it's Sunday afternoon, you're trying to get to HMB from east Cypress and northbound Highway 1 traffic is crazy, you'll have a right-of-way gap created by any of the following (who will have *their own right of way* over that northbound Highway 1 traffic).

-southbound Highway 1 turning in to east Cypress
-west Cypress going straight to east Cypress
-northbound Highway 1 turning in to east Cypress

Note also that *you have right of way over southbound Highway 1 traffic*.

So you only have to look to your left for a gap. That's the beauty of a roundabout in that situation -- you rock up, look to your left, wait for a gap (which will come) and go.

Where I've seen them break down is if traffic is terrible in both directions at the same time. And I've seen them removed after 20 years because a new neighborhood has been built, which stuffed things up.

Which again is not to say Caltrans wouldn't screw it up from the start!

When the roundabouts become completely plugged with heavy traffic, the slowly circulating vehicles will have to come to a complete stop to permit vehicles to enter from the sides. This is what happens at overloaded roundabouts. This does not help with the current difficulty of trying to make a left turn onto Highway 1 in heavy traffic times (do you know how to make a "coastside left turn"?). But the slowdown at all times and the mess during heavy use times will be orders of magnitude more "inconvenient" in sum than the current frustration with left turns. I live on the east side in Moss Beach, so I must make a left turn onto Highway 1 anytime I want to go south. It's a small price to pay compared to the potential 25 mph (and slower) roundabout hassles.

These would be nothing like roundabouts on streets in suburban areas. They would be nothing like the roundabout on Highway 1 at the south end of Fort Bragg. They would be nothing like the roundabouts at the northern freeway interchange in Arcata. They would be nothing like the roundabout on Townsend in S.F. Due to space restrictions, they couldn't possibly be big enough to let traffic flow at our current 45-50 mph. We are already trapped at busy highway times by traffic to the north and south of us. Let's not make the traffic situation even worse than it will already be with continuing overdevelopment in the midcoast neighborhoods and especially with the Big Wave and Cypress Point developments.

"We locals would be royally screwed by the vehicles that would quickly clog the hoped-for 25-mph roundabouts and prevent smooth entry of vehicles from the side streets, where vehicles in the roundabouts would have to come courteously to a complete stop to admit entry from the sides."

Carl, I'm not trying to disagree with your wider point, but at a roundabout it's the entering vehicle that gives way to the circulating vehicle.

In NZ we've had roundabouts for decades, from tiny little humps you can drive over right up to freeway 4-laners, and the one thing they've always been good at is allowing side traffic to get on to the main road.
That's why they've been installed -- when main road traffic becomes bad enough that locals can't get out, and a traffic light or stop sign would back the main road traffic up too badly. I'm not in a position to comment on how appropriate they would be there, but I've certainly gotten stuck trying to get on to Highway 1 from those streets and thought, "These buggers need a roundabout."

Dan, what is your source for "Highway 1 through Moss Beach and Montara is soon to get up to five controversial traffic roundabouts"? I have not seen any written suggestion for more than three: https://planning.smcgov.org/sites/planning.smcgov.org/files/Connect-the-Coastside-Final-Admin-Draft_Plan_Jan-2021.pdf pages 96 and 97.

Both California and Kentucky have plenty of existing roundabouts. Lots in Berkeley and a few scattered down in Hillsborough and Palo Alto. Coastsiders will no doubt figure them out.

Yes, #2 for roundabouts being a precursor to massive new housing projects from HMB all the way up to the Tom Lantos/Devil's Slide Tunnels. Count on dense housing coming to EVERY existing undeveloped parcel in unincorporated San Mateo County, including agricultural parcels that may previously have had riders on them preventing development.

There are many more roundabouts in California than the couple that Mr. Stegink mentions. Some work okay, some don't. During heavy traffic loads on highways, only stop signs and traffic signals are worse for backing up traffic.

Presently, the only coastside communities where traffic continues to flow on Highway 1 during periods, especially weekends, when there are far too many vehicles on the road, are Montara and Moss Beach. The rare backups are from miles away--the traffic signals in El Granada and Linda Mar and occasionally vehicles turning left into and out of the parking lot and beachgoers crossing the road at Gray Whale Cove.

So why the promotion of roundabouts in Moss Beach and Montara? Simply put, more planned overdevelopment leading to more planned overpopulation in our communities. A property-kiting scheme called Big Wave, which was happily approved and touted by the county, and which involves a stupidly located facility for developmentally disabled adults and their caregivers as a heart-tugging excuse for a much larger office and industrial park, will grossly overload the sometimes crowded intersection of Cypress Avenue and Highway 1 in Moss Beach. A smaller but still grossly out-of-scale and badly mis-located affordable Mid-Pen housing complex at the north end of Moss Beach is the main anticipated element in the push for traffic control at California and Highway 1. Urban highway planning, such as the naive Connect the Coastside scheme being pushed on us by the county, suggests the possibility for signaled intersections at both of these locations. Recoiling in what is almost brain-locking horror, some well-meaning local coastsiders, who have not been around long enough to have the experience to see through the self-serving developer-politician-bureaucrat-Caltrans behavior and who know that the worst traffic backups are caused at the traffic signals on the coastside, have, without any supporting real-world analysis, fastened on the idea of roundabouts as a way of avoiding signals and keeping vehicles moving in Montara and Moss Beach.

That would not happen. In the BEST of times and the lightest of traffic periods, current 45-mph traffic going through the circumference of the roundabouts that are suggested for the limited space available would be slowed to a maximum of 25 mph. There would be a 25-mph almost-dead zone between the neighboring roundabouts in Moss Beach. Even that most optimistic outlook does not account for through-drivers on Highway 1 being unfamiliar with roundabouts--abundant signage will only slow them as they try to interpret it--or for the difficulty side traffic from the neighborhoods would have in entering the roundabouts from dead stops. The backup of local commute traffic on Cypress might easily be as backed up as it would be at a signal, and the commute traffic at California would be much worse than now. Problem not solved.

But what of the weekends when we in Moss Beach and Montara are already often trapped by the morning and evening clogs to our north and south? Both travelers on Highway 1 and we locals would be royally screwed by the vehicles that would quickly clog the hoped-for 25-mph roundabouts and prevent smooth entry of vehicles from the side streets, where vehicles in the roundabouts would have to come courteously to a complete stop to admit entry from the sides. The roundabouts, contrary to flowing, would be plugged up with major backups forming at them on Highway 1. Locals familiar with roundabouts in various situations--where they work and where they don't--know this.

Everyone except those few who would get short-term financial benefits from the (also highway-plugging) construction loses long-term. Overpopulation ain't pretty.

California has had roundabouts for a while. The oldest one I can think of is the one in Stonestown to the west of the shopping center. There is one on Arnold Drive in Sonoma near the Hanna Boys Center.

Admittedly, this would be on a much larger scale, but people can figure it out. The traffic situation now is a total mess. I'm really glad I don't have to go anywhere near the south end of town or the Midcoast. I hope it helps.

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