For some that are not aware or just finding out, the city of Springfield is planning on installing 9 roundabouts (yes you heard correctly) between 42nd Street to 72nd.
"Traffic on Main Street will likely go up by 20-30% over the next 20 years and the risks from crashes will increase… unless we act now to plan changes that will save lives, reduce injuries, and lessen property damage." - Main Street Project
Do roundabouts work?
Actually yes. (Yeah, some do)
But will they work or are they even practical for Main Street?
The answer is NO!
So why 9 roundabouts on Main Street?
The claim: "• There is a serious transportation safety problem on Main Street. Springfield’s Main Street is consistently ranked as one of the most unsafe city streets in Oregon based on the severity and frequency of traffic crashes."(page 47) Springfield Main Street Facility Plan Vol. 1
"653 crashes between 2012-2016, 24 severe crashes and the loss of 6 lives… Only 3% of all crashes involve pedestrians… Intersections with the highest number of crashes, 42nd Street, Bob Straub, 58th Street, and 28th Street." - Main Street Safety Project
Roundabouts - they're safer, they save lives, they're more efficient, better for the environment.
(Personally, I think the engineers are the same engineers that design the NASCAR raceways. "What's he going to do next? He's going to make a left turn.")
Are they really safer? Well, if you're using a computer simulation to make that determination then it might look that way. But in reality, when you are working with people… Let's just say that not everybody stops at a stop sign.
"You can't fix stupid!" – Ron White
In my opinion, depending on the intersection and the traffic congestion, I feel roundabouts are more dangerous especially when you add pedestrians and bicycles to the mix.
First, keep in mind that "technically" a roundabout is an uncontrolled intersection.
let's take Harlow Road and Pioneer Parkway during rush hour as an example.
You have two lanes of traffic coming in from each direction. You are forced to stop before entering the roundabout and your main focus is to the left looking for a break in the traffic. Suddenly, one opens up and you prepare to enter the roundabout then out of the corner of your eye, you find that there is a pedestrian to the right of you that entered the roadway WITHOUT using the provided signal devices. (More on those signal devices later)
The car behind you, seeing that you've already started your move, has one eye on you however, their main focus is now on the roundabout and not noticing that you just slammed on your brakes.
If you think Harlow Road and Pioneer Parkway are fun, think about 42nd Street & 126th at Main street during rush hour.
"You need to pay more attention" no argument there, however, you have to take into consideration the different skill levels of drivers and that's why traffic lights are better on high-traffic multiple-lane intersections.
"Springfield’s Main Street is consistently ranked as one of the most unsafe city streets in Oregon based on the severity and frequency of traffic crashes. Over the past several years, the crash frequency on Main Street has been more than double the statewide average for urban arterial state highways. During the five-year studied period between 2012 and 2016 that was analyzed, there were 653 recorded crashes" (page 31) Springfield Main Street plan https://tinyurl.com/2p965juc
"The majority of the crashes along the corridor were rear-ended or turning crashes (80%)" (Page 32)
"79% of all crashes between 2012-2016, 305 rear end – 211 turning – 33 fixed object – 26 sideswipe – 20 pedestrian – 16 Angle – 7 backing – 6 miscellaneous – 3 Sideswipe (meeting) (page 32)
The fixed object could be items or islands within the turning lane. Example: having to stop short to get into the turn lane to make a left turn. Or, islands that are not highly visible at night during heavy rains.
• Impairment from drugs or alcohol contributed to only five percent of overall crashes on Main Street but accounted for 12.5 percent of fatal or severe injury crashes.
• Excessive speed and distraction contributed to approximately 10 percent of all crashes but were involved in a small proportion of fatal and severe injury crashes (less than half a percent).
• Approximately 77 percent of crashes occurred during daylight and just 14 percent occurred in darkness. This reflects typical travel patterns throughout the day – more people are driving, biking, and walking on Main Street during daylight hours– (Page 33)
"Since 2012, the city and ODOT Installed seven enhanced pedestrian crossings with marked crosswalks and medium islands according to recommendations in 2011 Main Street's safety study. The new crosswalks have increased pedestrian access to see for crossing opportunities" – (page 38)
"safer crossing opportunities" if used properly. However, (Speculation on my part) with the installation of these islands and the "suddenly turned on flashing yellow lights" may be a major contribution to the increase in rear-end crashes as drivers are suddenly stopping for these crosswalks. In my opinion, that would be like going eastbound on Seventh Street and there is a pedestrian waiting at the corner to cross the street and by law, you are required to stop to allow the pedestrian to cross. However, traffic and other lanes behind you are not expecting you to stop suddenly in the center lane of a non-controlled intersection.
So be on the argument of the efficiency of roundabouts, my argument for not adding any roundabouts on Main Street is that you're going to create more problems than what you're going to try to solve. Even the data that Springfield & ODOT is claiming of why MainStreet is so dangerous does not actually address the issue.
The end result, especially during the morning and evening rush hours, you're going to be backing up traffic for blocks.
One short example would be over by Thurston high school, when the school lets out and there's a lot of foot traffic on the crosswalk behind the 7-Eleven store, traffic has been known to backup all the way on the main street and beyond Walgreens.
And yes, they want to put a roundabout there as well.
Let's talk about roundabouts.
"Roundabouts "may" improve the safety of intersections by eliminating or altering conflict types, by reducing speed differentials at intersections, and by forcing drivers to decrease speeds as they proceed into and through the intersection.... In particular, single-lane roundabouts have been found
to perform better than two-way stop-controlled (TWSC) intersections in the U.S...Although the frequency of reported crashes is not always lower at roundabouts, the reduced injury rates are usually reported... Safety is better at small and medium capacity roundabouts than at large or multilane roundabouts.." - (US Department of Transportation page 103)
The US Department of Transportation refers to these as two different types of conflicts.
• "Queuing conflicts. These conflicts are caused by a vehicle running into the back of a vehicle queue on an approach. These types of conflicts can occur at the back of a through-movement queue or where left-turning vehicles are queued waiting for gaps. These conflicts are typically the least severe of all conflicts because the collisions involve the most protected parts of the vehicle and the relative speed difference between vehicles is less than in other conflicts."
• "Merge and diverge conflicts. These conflicts are caused by the joining or separating of two traffic streams. The most common types of crashes due to merge
conflicts are sideswipes and rear-end crashes. Merge conflicts can be more severe than diverge conflicts due to the more likely possibility of collisions to the side of the vehicle, which is typically less protected than the front and rear of the vehicle." -(US Department of Transportation page 106)
. Graphical depiction of collision types at roundabouts
Conclusion – there are arguments both pro and con. For Main Street? Bad idea.
And we haven't even touched on what it's going to do to the businesses on Main Street. Some are going to lose some of their parking lots, a few others are going to lose their business altogether.
For more information...
ODOTS TDS - crash reports start page https://tvc.odot.state.or.us/tvc/default.aspx