A $10,000 solution to dangerous Springwater path intersection

springwaterroundaboutsolution

Design concept for a roundabout on the Springwater Corridor path where it intersects with Oaks Bottom.
(Graphic: paikiala)

Last week we highlighted a known danger spot on the Springwater Corridor path. A “T” intersection with bad sight lines, high speeds, and a history of collisions and near-misses.

The Portland Parks Bureau is aware of the issue and is likely to address it via new signs and markings; but we all know simply adding more paint and signs often has limited impact on behavior. A BikePortland reader has a much more comprehensive solution. Paikiala, a regular commenter who often shares his detailed insights about traffic engineering, thinks the fix should be a small roundabout.

Paikiala says the California city of Davis, arguably the best city for biking in the country, uses roundabouts in situations like these. “Getting everyone approaching the intersection to slow down is the key,” he says, which is why he likes the roundabout idea.

And he estimates it’d cost about $10,000 — just 0.01% of Portland Parks’ annual budget.

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Ideally, he’d like to see a 20-foot diameter center island with an eight foot wide path around it and the circle would be offset (west) from the tunnel exit.

Other ideas readers shared included: convex mirrors (which PBOT apparently doesn’t install anymore due to maintenance requirements); an unlocked gate on the Oaks Bottom path that would require riders to dismount; a two-inch deep gravel pit to slow people down; a stop sign; an overpass or bridge; and so on.

Someone even mentioned a Hovenring-style solution, but even I’d have to admit that finding money for that is unlikely.

Speaking of funding, there’s still time to weight in on the Portland Parks Bureau’s 2015-2016 budget. Their online survey asks you to prioritize a list of projects (among them are matching funds for Gateway Green and the Citywide MTB Master Plan) and there is also room for write-in requests. Take the survey ASAP because it closes today (1/13) at 4:00 pm.

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soren
soren
7 years ago

An excellent solution to a recurrent problem in the portland area.

Also typo: paikiala

SilkySlim
SilkySlim
7 years ago

Less please! Drop the roundabout, paint the yellow lines, signs to yield only for those coming out from under the trestle.

Adron @ Transit Sleuth
Reply to  SilkySlim

That doesn’t really fix the collision problem. The roundabout actually does that through deterring the dangerous practice…

…but then of course, I suppose people do have to understand how to use a roundabout too. However, a roundabout if designed right, people will use it right regardless. A yield sign, still basically the same risks.

Eric
Eric
7 years ago

How about putting a yield sign on a $100 post at the edge of the main trail centered on the tunnel exit? Exiting the tunnel, you would stop and pass to the right of the post. This should have the same effect as the roundabout (discouraging fast turns into or out of the tunnel) as long as riders turning left into the tunnel would go around the post.

paikiala
paikiala
7 years ago
Reply to  Eric

All laws work only when everyone obeys them. If signs worked to control speed, we wouldn’t need so many police or traffic engineers. The premise of the Safe Systems approach to road safety is that road users will always and forever make mistakes. Road design can mitigate for those mistakes and reduce the possibility that the outcomes are fatal or serious injuries.

Gary
Gary
7 years ago
Reply to  paikiala

I think Eric’s point was that by putting the sign in the middle of the path, it is more than just a sign, it’s an obstruction that forces users to reduce speed. That said, the inevitable liability created probably far exceeds the cost of the much more elegant roundabout.

Opus the Poet
7 years ago
Reply to  Eric

Since the problem is the poor sight lines exiting the tunnel how will making them worse help? Riders can’t see traffic coming from the left until they are already blocking half the lane, so how will further obstructing vision to the left make things better?

David
David
7 years ago

As much as I am a proponent of better biking experiences and infrastructure I don’t believe this area is a priority. I bike through this intersection twice every day. Yes, it is less than ideal but it’s nothing a stop and look doesn’t fix. I would like to see resources spent elsewhere that have a bigger impact to a wider population.

Dan
Dan
7 years ago

What about reduced speed limits before the intersection there, like this? http://1.bp.blogspot.com/-fakQrzmVqso/UZzhiR-OP_I/AAAAAAAAAcU/Kon-Nz8Bb-0/s1600/IMG_0021.jpg

Lester Burnham
Lester Burnham
7 years ago

$10,000 solution when all people need to do is pay attention and slow down. Seems like that money could be better spent elsewhere.

Adam H.
Adam H.
7 years ago
Reply to  Lester Burnham

The problem is people aren’t paying attention nor slowing down. Good street design forces safe behaviors instead of relying on people to make the correct decisions themselves.

Todd Hudson
Todd Hudson
7 years ago

Putting that roundabout on that little sliver of Oaks Bottom Wildlife Refuge would probably require an environmental impact statement.

daisy
daisy
7 years ago

Part of the problem at that intersection is that folks on the Springwater on bikes can have some real momentum because it’s a low spot. Who wants to slow down on a downhill that’s followed immediately by an incline?

The problem is also that it’s a blind intersection. The roundabout might not slow down north-bound cyclists enough for folks to enter safely from the tunnel.

Is there a way to widen the path there on the riverside of the trail? Then thru-traffic could go to the outside/riverside of the path, and tunnel traffic (which should yield anyway, right?) would have some space to merge in.

paikiala
paikiala
7 years ago
Reply to  daisy

How would you compel through cyclists to move away from the underpass entry?

J_R
J_R
7 years ago
Reply to  paikiala

Move the north-south path toward the river by a distance of 10 or 15 feet. Start the transition 100 feet north of the underpass and 100 feet south of the underpass. Eliminate the existing asphalt pavement of the north-south path in the area where you have shifted the path to the west. Mainline cyclists will stay on the relocated mainline path.

paikiala
paikiala
7 years ago
Reply to  J_R

And the oft-vaunted off-road cyclists?
10 feet would be two triangles of AC, or one skinny rectangle, 10 x 100, or 1,000 square feet. At about $9/SF that’s $9k. Add to that the removal of the old trail AC. If you don’t remove the old AC, you’re going to need to find a way to keep through cyclists on the desired path. Maybe the old path space could become swales for drainage, but that requires excavation.

J_R
J_R
7 years ago
Reply to  paikiala

You’re right, it would be fairly expensive, but it would be less expensive than your roundabout. Curbs, as you propose for your roundabout, are really expensive.

Yes, the existing path would need to be removed. A swale would be a possibility, but I’d opt for prickly bushes and some big rocks. The reason for a gradual transition at least 100 feet from the underpass intersection is to reduce the tendency of the off-road cyclists to follow the straight line trajectory of the current path.

I certainly agree with you that the current design is problematic and that a geometric solution is probably in order. I simply disagree with the roundabout for several reasons I have enumerated. Not one to simply criticize, I offered up a different, better solution.

J_R
J_R
7 years ago

A roundabout at this location seems like a really stupid idea to me.

I do not believe for a minute that it will actually slow traffic on the Springwater approaches due to the downgrade; it will actually reduce sight distances for the northbound and westbound cyclists; and northbound cyclists will move closer to the wing wall for the underpass and to the central island of the roundabout as they seek to minimize their slowing.

Since cyclists are rather reluctant to slow down (remember the outrage at the speed strips on Hawthorne Bridge that was discussed on this forum?), the solution is to increase sight distance and give cyclists and pedestrians a bit better chance of seeing one another. This can be accomplished by slightly shifting the entire path to the west, toward the river by ten feet. That looks to be the same distance proposed for the westerly edge of the roundabout.

Jonathan Gordon
Jonathan Gordon
7 years ago

First of all, I can’t believe people are complaining that $10K is too expensive. That’s a rounding error. It’s nothing.

Second of all, while yes, it would seem a stop and a look are all that are required, it appears that’s not working. From the initial article it sounded like the rider who was coming from under the bridge did stop and look but the mere act of edging forward was enough to cause a collision.

If $10K can be spent to prevent just one more collision over 10 years it will have been well worth it.

meh
meh
7 years ago

Portland has a $1.3B budget, so that $45M for street fees everyone is complaining about is just a rounding error.

This is the attitude about other peoples money that causes the problems we now have. At the local level it’s only $10K, at the state level it’s only $1M at the federal level it’s only $100M. Everytime I hear “it’s only….” I cringe because we have “it’s onlied” ourselves into deficits and debt.

Chris Anderson
Chris Anderson
7 years ago
Reply to  meh

The counter-argument being that local budget fights are penny-wise and pound-foolish. When the smartest folks in the room are saying you can’t get a better return on investment than by building bike infrastructure, it pains me to see budget fights about this at all. If we built every single bike wishlist item we can imagine, it would cost a fraction of the proposed CRC, with a multiple of the benefits. May as well do the hovenring, it pays for itself!

davemess
davemess
7 years ago

“Second of all, while yes, it would seem a stop and a look are all that are required, it appears that’s not working.”

Does it appear that it’s not working? How many serious incidents are actually happening at this location?

Mike
Mike
7 years ago

Yeah, 10K is too expensive when a cheap stop sign should suffice. I guess there is absolutely no confidence that a cyclist would actually obey a stop sign so go ahead and drop 10K.

Jonathan Gordon
Jonathan Gordon
7 years ago
Reply to  Mike

We’ve actually had specific comments that demonstrate that even with stop sign compliance, injuries result:

http://bikeportland.org/2015/01/08/parks-bureau-considering-changes-tricky-springwater-path-intersection-130688#comment-6095029

$10K would be well worth the cost if we can prevent another of these types of collisions.

was carless
was carless
7 years ago

Considering that 90% of the bike traffic is NOT turning at this spot (disclaimer: I live off of Oaks Bottom and use this route), then this roundabout will negatively impact quite a few people.

All you really need are better sight lines. Pushing the underpass path a bit further to the west before it intersects the main trail would give people coming out (which is the real danger) visibility before the actually pull out would solve this.

paikiala
paikiala
7 years ago
Reply to  was carless

Traffic diverters on neighborhood greenways inconvenience a lot of people, also.

Brian
Brian
7 years ago

If that roundabout will lead me into the trails right there that I will be able to ride legally, I am all in.

MaxD
MaxD
7 years ago

If people can’t be bothered to slow down an take look at a blind T-intersection, what would compel these same people to go the right way around a roundabout? I see bike short-cutting the little roundabouts in Portland (and in Vancouver BC when I lived there) all the time! If you come through te tunnel and want to go left, I believe a high percentage of people would simply go left (the wrong way) and create a bigger danger.

bloodcircus77
bloodcircus77
7 years ago
Reply to  MaxD

My thoughts exactly. Even less time to react and less space to take evasive action.

Also creates a hazard for those traveling in poor visibility, like fog, dusk or similar.

paikiala
paikiala
7 years ago
Reply to  bloodcircus77

Presuming you don’t slow down, but roundabouts are fairly conspicous objects in the pathway.

Psyfalcon
Psyfalcon
7 years ago
Reply to  paikiala

Have you ever seen people do that in cars? Plenty of people do on Woodward (near the HS) do. They slow, yes, but then they gun it the wrong way around the mini roundabouts. This isn’t a disaster since everyone can see what is happening.

Here, you still have downhill traffic, now facing head on bike traffic without improved sightlines.

gutterbunnybikes
gutterbunnybikes
7 years ago
Reply to  MaxD

And depending on what’s going on to edge/curb the circle, how long till a dirt path is worn right through the middle of it.

paikiala
paikiala
7 years ago

The middle of roundabouts is raised up and less hospitable to ride over than going around.

gutterbunnybikes
gutterbunnybikes
7 years ago
Reply to  paikiala

To some that would be a deterrent, others would likely consider it a challenge.

paikiala
paikiala
7 years ago
Reply to  MaxD

In those instances of neighborhood traffic circles where you observed short-cutting, or should I say, illegal turns, did you observe a crash? If not, why not?

davemess
davemess
7 years ago
Reply to  paikiala

no, lack of traffic (as most of these roundabouts are on lower trafficked streets).

paikiala
paikiala
7 years ago
Reply to  davemess

I have observed the same. Where’s the harm, if the sight distance is good?

Psyfalcon
Psyfalcon
7 years ago
Reply to  paikiala

There is still no sight line on the Springwater because of the underpass abutments and the slope.

MaxD
MaxD
7 years ago
Reply to  paikiala

better sight lines, I think. These are mostly small circles in an intersection (EX: NE 7th an Tillamook)

groovin101
groovin101
7 years ago

Regarding the survey, if anyone else is scratching their heads about some of the questions (ex: what’s a Loo Licensed Plumber?), this doc might help: https://www.portlandoregon.gov/parks/article/514783

Ted Buehler
7 years ago

For the record, Davis only has Bike Roundabouts on
* flat paths (not on hills with higher speed differentials)
* intersections with high volumes on multiple legs.

No Roundabouts as traffic calming devices, or to allow safe entry into the traffic stream from a low-volume leg.

Also, Davis has occasional problems with experienced riders having wipeouts in the circles. Taking them too fast, or not positioning their bikes correctly in the fairly complex in-around-out movements.

Not to be a naysayer, just adding data.

Ted Buehler

Ted Buehler
7 years ago
Reply to  Ted Buehler

If you want to learn more about infrastructure in Davis, I did my masters thesis on the topic in 2007, and will be presenting at the PBOT Bicycle Brownbag this Thursday, Jan 15, at noon.

https://www.portlandoregon.gov/transportation/article/144945

Edward
Edward
7 years ago
Reply to  Ted Buehler

PBOT has a … Brown bag bike lunch event on a monthly basis?!?

I’m already trying to envision the nearest safest bike parking to City Hall so I can go, because I’m guessing they’re not going to erect a bike corral out front.

paikiala
paikiala
7 years ago
Reply to  Edward

City Hall has racks on 4th (I think) and definately around the Portland Building just south.

gutterbunnybikes
gutterbunnybikes
7 years ago
Reply to  Ted Buehler

Can you really call them “experienced riders” if they’re wiping out by riding too fast (or leaning too much) on a paved roundabout?

Seems to me that wiping in this situation is giving them the experience they lack. It’s not like it’s difficult maneuver.

Ted Buehler
7 years ago

The two instances I’m aware of were faculty who had been riding on campus for 20+ years.

One was on one of the 1960s roundabouts, he may have gotten cut off by another bicyclist or otherwise ended up nudging his tire against the yellow buttons that define the center ring, lost balance, and fell hard. Broke his hip, as I recall.

The other was in a brand new roundabout that had a tight radius, reverse superelevation and possibly some gravel on the roadway. So, bad engineering. But still, the fall tore up the insides of the man’s knee pretty good.

The roundabouts are are known to confuse new students who are inexperienced bicyclists, since there’s complex merging issues when you have high volumes of high speed and lower speed traffic all moving through there together. But younger folks can usually take a fall without serious injuries, or heal more easily from broken bones.

Since very few bike-bike crashes are ever reported, it’s reasonable to assume that with two anecdotes with injury crashes by experienced cyclists and a known pattern of crashes with inexperienced cyclists that the bike roundabouts can cause types of crashes that don’t occur at conventional intersections.

Roundabouts work quite well for moving large volumes of slow speed bicyclists through intersections with 3 or more busy legs.

In the Springwater case, I suspect safety could be better served with a very well marked “STOP” sign on the T leg, and a “Slow: [T Intersection] sign on the two main legs. And improving visibility by cutting brush, and ideally pushing the whole path system out a few feet from the railroad bridge. This is how they’d do it if it were a T intersection for cars with low volumes on the “T” leg — — install additional hazard warnings on the main route and emphasis on a stop sign (flashing red light, two stop signs, big white stop bar, “caution: cross traffic does not stop” sign, etc).

But, I like bike roundabouts in many circumstances, and I may well be completely wrong in my opinion as to their applicability here. In any case, kudos to paikiala for introducing them as a novel proposal for discussion.

Ted Buehler

gutterbunnybikes
gutterbunnybikes
7 years ago
Reply to  Ted Buehler

Making excuses for bad driving on a car or bike is just that excuses. “Experts” wouldn’t have fallen in either of those cases, because they would have been aware of the road conditions and presence of other riders and adjusted their behavior to safely navigate the situation.

Do we all have our moments in lapses of judgment? Sure – we’re all guilty. But we can’t condemn people who drive automobiles poorly, and make silly excuses for our own poor judgements while riding a bike.

Ted Buehler
7 years ago

Here’s some streetview links to Davis’s Roundabouts — they’re in a very different operating environment (flat, well lit, slow speed, good visibility) than this location (dark, poor visibility, higher speed traffic). I think there’s about 18 of them now, with 4 built in the last 10 years.

1960s era Roundabouts, on former streets, central campus
Hutchinson and California
http://goo.gl/maps/nPZSD

Shields Ave & East Quad
http://goo.gl/maps/dJhXL

2000s era roundabouts, on roads designed as multi-use paths
Bainer Hall 1
http://goo.gl/maps/72oZT

Bainer Hall 2
http://goo.gl/maps/82zBe
(Mind the Bollards!)

Arboretum and B (Smallest roundabout)
http://goo.gl/maps/kXDFQ, ~1990?

Sprocket Bikeway (Largest roundabout)
http://goo.gl/maps/IQTE4 ~_1970s?

FWIW,
Ted Buehler

Ted Buehler
7 years ago
Reply to  Ted Buehler

While we’re on the topic, UC Santa Barbara also has a few Bike Roundabouts of various sizes and configurations.

http://goo.gl/maps/wu8Gp
http://goo.gl/maps/Jhg5H
http://goo.gl/maps/Ur0oO
http://goo.gl/maps/W00GF
http://goo.gl/maps/qpnaO

Spiffy
Spiffy
7 years ago

those yellow/black lines need to be curbs or else people will just swing wide to keep their speed up…

paikiala
paikiala
7 years ago
Reply to  Spiffy

They are.

J_R
J_R
7 years ago
Reply to  paikiala

Putting curbs adjacent to the bike path is another disaster waiting to happen. Remember how people complained about the 1/8 inch high speed bumps on the Hawthorne Bridge and what a hazard they were?

paikiala
paikiala
7 years ago
Reply to  J_R

Caution in road users cannot be created unless they feel less safe. Sorry, but being safer usually means slowing down, and many people equate slowing down with inconvenience. The cost to impose a speed limit and enforce it adequately enough to achieve similar results is much higher.

Jonathan Gordon
Jonathan Gordon
7 years ago

As one of the people responsible for urging change on the Hawthorne Bridge bumps, I am baffled as to how you can compare these two pieces of infrastructure.

Aaron
Aaron
7 years ago

I’m usually one to speak out about over doing it on some of these “bike safety” projects, but this one seems to be a pretty good idea.

ralph
ralph
7 years ago

Didn’t read all comments, so don’t know if this was mentioned. Northbound stilll has potential collision. Consider how cars were redirected on highway 99 and Southend rd between Oregon city and canby. Much cheaper with a few plastic posts and creativity.

bloodcircus77
bloodcircus77
7 years ago

Maybe PBOT will screw this one up as bad as they did on Williams. Like reverse traffic flow, add some lane changes and stuff… More curbs, bumps, and transitions! More barriers to riding a bike in a straight line! More focus groups! More revisions! More bureaucracy!

steve
steve
7 years ago

Let’s consider equitable resource distribution and fix the blind corner at the 205 trail and Burnside. East side needs some love to. I travel through both intersections with regularity and have far many more close calls at that blind corner on Burnside. Is this a data driven decision?

Adam
Adam
7 years ago
Reply to  steve

Yes, please. I ring my bell as loud as I can every time at that corner, but still have close calls. Between freeway noise, and the wall blocking sound (as it is designed to) audible warnings are pretty worthless.

Further south is another problem spot. There is another blind corner, with a left turn as well at the intersection of the Main St Max station pedestrian bridge that crosses the freeway and the 205 path. I’ve witnessed one bad crash and numerous close calls there.

There are simple fixes here. Remove even just ten feet of the wall, or at least make it only four feet tall. And for the further south blind corner, have the property owner remove or lower the hedges. I believe it is a care facility run by the Oregon Department of Human Services.

Jeff
Jeff
7 years ago
Reply to  Adam

Man, I blocked that out. A common commute route of mine was to head south on the trail and take a right over the MAX tracks and into the westbound Burnside bike lanes. From that angle, you can’t see an eastbound Blue Line MAX train until it’s right on top of you.

greg byshenk
greg byshenk
7 years ago

I’m not sure it’s the best option, but a bicycle roundabout is an interesting option.

Here are two that I’m familiar with (in somewhat similar sitauations) from Leiden, NL:

http://goo.gl/maps/4YK0x
http://goo.gl/maps/V5gVw

greg byshenk
greg byshenk
7 years ago

Sorry, it looks like that first ‘short url’ didn’t work.

Try: http://goo.gl/maps/2HFKU

doug B
doug B
7 years ago

I currently ride this route almost everyday and I have to agree with the commenter above, the best solution for this area is to move the path a few feet towards the river(there seems to be room there) and extend the path coming out from under the overpass. This would make the sightlines far better and enable everybody to see eachother and react accordingly.

paikiala
paikiala
7 years ago
Reply to  doug B

How would you compel cyclist on the mainline to move over?

J_R
J_R
7 years ago
Reply to  paikiala

Move the north-south path toward the river by a distance of 10 or 15 feet. Start the transition 100 feet north of the underpass and 100 feet south of the underpass. Eliminate the existing asphalt pavement of the north-south path in the area where you have shifted the path to the west. Mainline cyclists will stay on the relocated mainline path.

paikiala
paikiala
7 years ago
Reply to  J_R

It would cost more than $10,000.

doug B
doug B
7 years ago

Also, while I like the idea of having round-a-bouts in general, and think people should be more courteous when it gets congested, this does not seem like a great location for one. It is at the bottom of a hill going both directions on the most used route, and it still wouldn’t solve the problem of being able to see other people when they are coming out of the tunnel or them being able to see people heading north. Also, like someone else mentioned- since the tunnel is infrequently used I could see people heading south turning into it to go the wrong way in the round-a-bout instead of looping all the way around.
I don’t think the main problem is that people are going too fast(although people generally go pretty fast, I think to build momentum to get up the hill), its that you can’t see other users until you or them are right on the trail already.
Personally, I really don’t mind slowing for other people, especially on the Springwater. But I think it might grate on my nerves after slowing way down coming down one of those hills before making my way up the other side and only seeing someone coming out of the tunnel maybe once every 25 times I pass.

Twistyaction
Twistyaction
7 years ago

I don’t think this should be a higher priority than dealing with illegal camping and chop shops along the Springwater. Make riding on the path at night feel safe first, then worry about optimizing this intersection.

Rita
Rita
7 years ago

I like the roundabout, but agree that it’s a solution for a small number of collisions, and detrimental for most users.

How about the user community getting a couple half-whiskey-barrel planters (with reflective tape and maybe a solar power flasher for the first winter), and try out a couple configurations?
1: 3 planters in center making a round about
2: 2 planters making a choke point on the path-side of the underpass (making a narrower outlet from the T intersection, which will encourage those folks to slow down, and allows them to be visible to straight-travelers before they turn)
3: Other ideas?
Put a sign on all three directions with a link to surveymonkey where the trail users can comment.

Harald
7 years ago

Madison (Wisc.) recently opened a bike roundabout: Gallery. Different situation, there, though.

paikiala
paikiala
7 years ago
Reply to  Harald

Intersection planter, maybe, roundabout, no.

Roundabouts have specific rules and forms. All entering traffic yields to traffic in the circular roadway. All traffic goes around the central island counterclockwise – it’s one way. All entering traffic is deflected to the left of the central island with splitter islands on the approaches. The deflection is key to slowing down the interactions and upping the safety. The fastest path for an automobile roundabout should not exceed 20 mph. For a bike roundabout, it would be more like 5-10 mph.

Edward
Edward
7 years ago

This intersection is always dangerous.

I’ve had a number of scary near misses here. It’s just a really bad mix of a downhill/uphill blind merge + the occasional guy with dogs staggering out of the woods.

Widening the path sounds great, but is it feasible? Another section of path collapsed north of this spot (yes, with a much steeper slope and much closer to the water). I also don’t know who owns the land and about rights of way, etc.

It seems like cheapest fastest solution might be to deploy a couple of big cement planters to create (a) bike diverter(s) — the same way car diverters work to slow cars in city streets could be used to force bikes to slow down to navigate this dangerous intersection.

Chandler
Chandler
7 years ago

Not to be the downer here but why can’t a wide triangular be as effective? The should be greater sight and less confusion on the “roundabout” as well as those who well go the shortest way possible.

I view roundabouts as path hazards. One more thing to hit. But then again, I am just a tourist in your town.

J
J
7 years ago

The roundabout is a bad idea. There are cyclists with no lights riding all the time and you can get a little speed up in that dip. Any obstruction in the path is gonna send people over the bars.

The real solution is to have the Oaks Bottom connector meet the Springwater north of the dip. Then it would be super visible and the speeds would be better in check. The connector would have to cross the tracks and it’s probably more expensive and planning intensive, but everyone would be served well.

Opus the Poet
7 years ago

Ted Buehler
The two instances I’m aware of were faculty who had been riding on campus for 20+ years.
One was on one of the 1960s roundabouts, he may have gotten cut off by another bicyclist or otherwise ended up nudging his tire against the yellow buttons that define the center ring, lost balance, and fell hard. Broke his hip, as I recall.
The other was in a brand new roundabout that had a tight radius, reverse superelevation and possibly some gravel on the roadway. So, bad engineering. But still, the fall tore up the insides of the man’s knee pretty good.
The roundabouts are are known to confuse new students who are inexperienced bicyclists, since there’s complex merging issues when you have high volumes of high speed and lower speed traffic all moving through there together. But younger folks can usually take a fall without serious injuries, or heal more easily from broken bones.
Since very few bike-bike crashes are ever reported, it’s reasonable to assume that with two anecdotes with injury crashes by experienced cyclists and a known pattern of crashes with inexperienced cyclists that the bike roundabouts can cause types of crashes that don’t occur at conventional intersections.
Roundabouts work quite well for moving large volumes of slow speed bicyclists through intersections with 3 or more busy legs.
In the Springwater case, I suspect safety could be better served with a very well marked “STOP” sign on the T leg, and a “Slow: [T Intersection] sign on the two main legs. And improving visibility by cutting brush, and ideally pushing the whole path system out a few feet from the railroad bridge. This is how they’d do it if it were a T intersection for cars with low volumes on the “T” leg — – install additional hazard warnings on the main route and emphasis on a stop sign (flashing red light, two stop signs, big white stop bar, “caution: cross traffic does not stop” sign, etc).
But, I like bike roundabouts in many circumstances, and I may well be completely wrong in my opinion as to their applicability here. In any case, kudos to paikiala for introducing them as a novel proposal for discussion.
Ted Buehler
Recommended 4

The few wreck reports I can find are all here in BikePortland (one linked above) and they all are because the sight lines for the traffic entering from the tunnel are so restricted that the rider has to block half a lane on the path before he or she can see oncoming traffic on the path. My back of the envelope/bar napkin analysis is the only thing preventing mass carnage at this intersection is the lack of traffic on all 3 legs of the intersection, but particularly the legs approaching from the left of the tunnel and from the tunnel itself. Stop signs are not going to clear up the sight lines so that entering traffic from the tunnel does not block the path from the left before they can see that traffic. The roundabout does by allowing a gradual merge instead of pulling across the lane.

Jr Rider
Jr Rider
7 years ago

I have ridden through this dip twice daily almost every work day for 4 years. Who has brought this forward as dangerous? Why would we spend 10k on unnecessary infrastructure for a non existent issue? They haven’t even fixed the tear in the pavement at the bottom of that dip in the last 4 years. Let’s spend some money on he travesty of the bus and max crossing at the Rose Quarter instead. Or the Ross Island gravel interchange as you leave the path heading to OMSI.

Skid
7 years ago

All that is needed is a stop sign and common sense.

Jonathan Gordon
Jonathan Gordon
7 years ago
Reply to  Skid

There’s plenty of posts on here explaining why the current Stop sign configuration isn’t cutting it. I totally respect that you may disagree, but it doesn’t add much to the conversation unless you explain yourself beyond “common sense”.