After taking its "field trip" to a grass berm, Alameda City Council reconvened in its chambers at City Hall and voted on the proposed designs for the Clement Ave/Tilden Way project. By a 5-0 vote on March 21, the entire City Council approved staff and consultant's proposed designs for a "modern" roundabout and other safety improvements.

That's nice news for this project — for which staff have been laying groundwork for years — and it highlights some more open questions as Alameda continues to consider modern roundabouts for more transportation improvements elsewhere, including the cross-island corridor along Lincoln Ave.

A unanimous vote

Is it surprising that it was a unanimous vote in favor? On the one hand, yes, it's a contrast with the noise and opposition against other recent votes on transportation projects.  On the other hand, it's less of a surprise because this project avoids touching the most sensitive of nerves in Alameda related to transportation issues.

While this project will reduce some sections of roadway from two thru-lanes to one and will remove a few on-street public parking spots (all in the interests of safety and overall efficiency), this project does not re-allocate street right-of-way from motorists to cyclists. Zero-sum arguments about everyday drivers vs. the bike lobby were less of a factor in this project, as has been in other traffic safety projects around Alameda. This project just happened to not involve some of the "geometric" (space) constraints that require tougher tradeoffs elsewhere around Alameda.

The speed of progress

If the final adoption of this project seemed swift, that was only due to years of preparation by Alameda's transportation staff. It was in 2016 that the city began the groundwork for this project, by submitting a first grant application to the Alameda County Transportation Commission for funding:

schedule from 2016 to 2024 for the Clement Ave/Tilden Way project
Schedule from 2016 to 2024 for the Clement Ave/Tilden Way project. Source: project website.

From grant application to construction, this single project is estimated to take eight years. That's a long time — but also probably not unusual for transportation projects.

The project had to be funded by the county; some land had to be acquired from the company that previously operated a railroad; incremental actions and contracts had to be approved by Alameda City Council; plans had to be drafted and refined based on public input...

It's to Alameda city staff's credit that projects like these are successfully shepherded through so many years of incremental stop-and-go, hurry-up-and-wait progress.

That's projects — plural — because it's important to have multiple projects like this in various stages, to take full advantage of funding opportunities when the county, state, and federal government offer grants to cities like Alameda, and to ensure that another project moves forward even when one project is held up by unique roadblocks.

Alameda's transportation staff punches above its weight, but is still relatively small. Expanding the city's staff would enable the city to run more projects in parallel, pursue more external funding, and address more of the city's needs to improve transportation infrastructure with both immediate improvements (like "quick build" projects) and long-term improvements (such as full rebuilds like this project at Tilden/Clement, new programs, and revised policies).

Single lane vs. two lane modern roundabouts

An eagle-eyed reader of one of my past blog posts on this project immediately wrote me to point out that the diagrams I included of modern roundabouts in that post had a problem — they illustrated roundabouts with two lanes of thru traffic:

Source: Washington County Roundabout U

Those are big roundabouts. They may be slightly safer than orthogonal intersections, as they still horizontally deflect drivers from traveling straight through the intersection. However, the safety benefits are more muted, compared to a single-lane roundabout. The experience of a two-lane roundabout is also more complex for drivers, and more challenging for pedestrians to cross. It's questionable whether a two-lane roundabout would be a net improvement for any existing intersection in Alameda.

It's good that the roundabout to be installed at Tilden/Blanding has one lane of thru traffic. It will be slower and smoother for everyone, while still moving more than enough traffic.

As the lead consulting engineering said at the City Council's "field trip" session, this design will be sufficient to move 120% of current auto traffic volumes at peak hours. That is, 20% more than the number of cars and trucks at the busiest hour on weekday mornings and the busiest hour on weekday afternoons.

In contrast, there's potential for two-lane roundabouts to appear in other projects around Alameda.

A potential two-lane roundabout in west Alameda

For example, initial plans for the Lincoln Ave/Marshall Way/Pacific Ave Corridor Improvements project included a roundabout with two lanes at Wilma Chan Way (Constitution Ave):

Preliminary draft concept of Lincoln Avenue/Marshall Way/Pacific Avenue Corridor Improvement Project presented to Alameda (city) Transporation Comission on February 15.

After critical feedback from residents, Bike Walk Alameda, and Bike East Bay, the proposed roundabout was removed from the plans that are now being circulated in advance of a City Council hearing scheduled for April 18:

From the updated detailed concept to be presented to Alameda City Council on April 18.

Both the preliminary and updated plans for Lincoln Ave. include another modern roundabout, to be located further to the west at Fifth St. This modern roundabout is designed with a single lane, so I won't discuss it further in this blog post. Also to the west is a one-lane modern roundabout being planned at Pacific Ave. and Main Street (as part of the separate Central Ave. Safety Improvement project – again, a beneficial sign of multiple projects being implemented in parallel).

Do two-lane modern roundabouts fit anywhere in Alameda?

There might be a disconnect on the two-lane roundabout proposed at Wilma Chan/Lincoln/Eight, since the city has separate engineering firms responsible for the Clement/Tilden roundabout and for this new Lincoln Ave project.  (Fortunately, it's the former engineering firm — the ones promoting single-lane roundabouts — that is also on retainer for providing more general advice on modern roundabouts to the city.)

The best way to resolve this disconnect would probably be to limit all modern roundabouts within Alameda city limits to one-lane modern designs. That would be in the best interests of safety for all travelers.

Still, there could be a small number of locations around Alameda that handle larger volumes of autos on four-lane roads that warrant studying two-lane modern roundabout designs. (Studying — in order to identify pros and cons — but only proceeding with a two-lane roundabout if the tradeoffs are truly a net positive.)

The city has recently just updated its street classifications and has a designation exactly defined for these locations, called "Gateway Streets":

Mobility Element Street Classification Appendix adopted by Alameda City Council on January 17, 2023.

Wilma Chan Way

Let's zoom in on Wilma Chan Way (until recently known as Constitution Way):

Wilma Chan Way is designated as a Neighborhood Connector Street (dark blue) when it reaches Lincoln Ave and Eight St. So, by my proposed policy, a two-lane modern roundabout would be out of consideration for this intersection. Two-lane modern roundabouts would still be open for study at intersections along Wilma Chan Way closer to the tubes.

This hints at the real problem with that two-lane modern roundabout proposed in the initial plans for Lincoln/Wilma Chan/Eight St: that intersection depends upon both Lincoln and on Wilma Chan. Redesigning that intersection properly requires also reconsidering the length of Wilma Chan Way.

Wilma Chan Way is, in its current form, a "car sewer" that divides and separates large portions of Alameda. It's unfortunately fitting that it's now named for an Alameda resident who was killed by a driver while she was on foot. The road is itself the site of multiple fatal crashes that have killed pedestrians on foot, drivers, and motorcyclists.

Wilma Chan Way is desperately in need of a rethink. Unfortunately, the Lincoln Avenue/Marshall Way/Pacific Avenue Corridor Improvements project is not going to involve that rethink. (There are already three different street names in the project title, after all!)

Next go 'round the roundabout

At a minimum, the city should not reinforce broken status quos. It's good to see that the originally proposed two-lane modern roundabout at Wilma Chan/Lincoln/Eighth St. has been removed from concept plans.

But that does leave an open question to be answered: Do two-lane modern roundabouts have any place in Alameda?

Moving ahead with the (modern) roundabout on Tilden Way and thinking ahead to the next ones on Lincoln Ave