Sunday, April 18, 2010

Roundabouts


It is not my place to speak for the other members of the Hilliard School Board, but as a private citizen, I am most definitely not a proponent of the Hilliard Triangle Project as currently being implemented by the City of Hilliard.

I actually like roundabouts – when they are located in appropriate places and properly designed. Unfortunately, I do not believe either is the case with this particular project. I believe this particular design will make the traffic problems worse during peak periods, and more importantly, create much more danger for the children who need to cross those intersections, given that this area has the greatest concentration of school buildings in our district. Kids walking to/from Hilliard Station 6th Grade Building, Scioto Darby Elementary, Memorial Middle School, Heritage Middle School and Darby High School will need to cross these streets, in some cases multiple times.

For those who have not heard about this project, here's the simple explanation: The two intersections at Main St and Cemetery Rd and Main St and Scioto-Darby Rd are going to be replaced by two roundabouts. At the same time, the "Y" intersection just west of there where Cemetery Rd and Scioto Darby Rd meet is being reworked to become a 90° intersection with a traffic light. The City of Hilliard has published a Frequently Asked Questions page that provides many more details, and a lot of opinion presented as fact.

What I write here is opinion as well, of course. My hope is to point out what I believe are legitimate and reasoned concerns. It is up to you to decide who makes the better case.

So, as I said, I like roundabouts. I believe the ones on Britton Parkway and Hayden Run Rd are generally good designs, and are functioning well. We got our first taste of roundabouts in England, where they are often used at busy and complex intersections, including as freeway interchanges.

One of the arguments in favor of roundabouts is that they're safer precisely because they force drivers to engage and think about what is going on around them, something that isn't quite so necessary when an intersection is controlled by standard traffic lights. While I believe this to be true, I suspect that this argument was made in the days before cell phones and texting, two practices which make driving in general more dangerous (especially for motorcycle riders like me!), and especially so at intersections where the traffic never stops.

I would be in favor of putting short-range 'cell phone signal killers' (and they absolutely exist) in roundabouts, except that I'm sure that if a person's cell phone suddenly went dead, he/she would become even more distracted while trying to figure out what was going on (although I once had the opportunity to observe an experiment with such a device, and while most people quickly discovered that their signal had been lost, one person spoke on for quite a while before realizing that the other party wasn't responding).

While not a traffic engineer, I have been involved in data telecommunications all my adult life, and the problems of auto traffic engineering and data traffic engineering are remarkably similar. The closest equivalent to a roundabout in a data network is a router. A router receives data from many incoming data streams, sorts the streams by destination, and sends them on via the appropriate path.

In most cases, routers work pretty well, but there can be problems. One of the major problems is congestion, when so much data traffic is coming to the router that it is unable to keep up. When that happens, one of more of the incoming streams has to be stopped until the congestion clears, causing users of the network to experience delays and sometimes interruptions. While working for the largest network operator on the planet, UUNET, we saw a couple of occasions when congestion became so bad that entire sections of the country had service disruptions as the congestion problem propagated out from the original source, just as happens when there is a big wreck on I-270 and lots of people bail out to the surface streets, congesting them as well.

This is one of the things which I believe will happen at the Hilliard Triangle roundabouts during times of peak traffic flow: morning rush hour, afternoon school dismissal, and evening rush hour. The situation is entirely predictable: traffic entering from one of the directions will become dense enough to completely congest the roundabout, forcing traffic from the other three directions to stop and wait until the traffic from the first direction subsides. Because roundabouts have a counter-clockwise flow, the traffic from the next counter-clockwise direction, which has been backing up while waiting for a shot at the roundabout, will jump into the roundabout and fill it until that line empties, and so on around the circle.

This phenomenon will be further exacerbated in our case by the fact that there is another roundabout right next to the first, where the whole congestion scenario happens again. Take for example that it is evening rush hour, when there is a lot of traffic which has exited I-270 and is heading westbound on Cemetery Rd. Some of that traffic will need to go south on Main St, as evidenced by the number of cars which today jam up in that intersection. A car traveling this route will enter the Cemetery/Main roundabout at the eastern portal, travel 270° around the roundabout to go south, exiting on Main St, only to be immediately dumped into the second roundabout. There the driver will need to go to the opposite exit to continue south on Main St. If that roundabout becomes congested, traffic could back up into the other roundabout, bringing traffic at this key junction to a standstill. Tempers will flare, and accidents will happen.

Which brings me to my greater concern: pedestrian safety – in particular the safety of the children who will be crossing those intersections on the way to and from school. You may recall that we've already had one death near there – crossing guard Dianna Sharp, who is credited with saving a child by putting her own body in the way of a dump truck westbound on Scioto Darby Rd.

The views expressed on the City of Hilliard website include this:

"The pedestrian environment is much safer with roundabouts. Intuitively this may not initially make sense because pedestrian WALK/DON'T WALK signals are removed at roundabouts; however, large intersections with wide pavements to cross, many turn lanes, and higher speeds do not provide an environment that is inviting or conducive to pedestrian mobility and safety."

But it seems to me that with appropriate traffic light sequencing and WALK/DON'T WALK signs, you can create periods of time – just during school hours – when all traffic is momentarily brought to a stop, and you can safely maneuver kids across the intersection, especially with the supervision of crossing guards. With the roundabouts, traffic does not come to a complete stop, except to yield to pedestrians – if they are noticed.

So let's go back to the argument that roundabouts are supposed to be safer because they force drivers to think. In reality, when you come to a roundabout, there is a significant amount of information to process, and you get all of that information visually. You will be primarily looking for opportunities to weave your 3,000lb vehicle moving at 25mph or so into a traffic flow of other 3,000lb vehicles also moving at 25mph. How likely are you to be looking for a 4ft tall, 60lb kid about to cross the street at your exit point? No very likely, I fear. Especially so for drivers yapping and texting on their cell phones, and remember, we'll have lots of teenage drivers from both Darby and Davidson high schools using these intersections.

The opportunity to have cars mowing down kids is unacceptably great, in my opinion.

Both of my key concerns are solvable. It just takes money. Instead of two small adjacent roundabouts, a larger roundabout could have been constructed, providing a single sorting point for Cemetery, Main and Cemetery traffic. It would almost certainly mean buying the Donatos property, which the City of Hilliard has the power to do through eminent domain even if Donatos is unwilling to sell, but the cost would have been much greater. I think this is an incredibly short-sighted decision on the part of the City's leadership. Once built, these double-roundabouts are apt to be a nightmare long after they leave office (although, we no longer have term limits in Hilliard!)

The pedestrian concerns could have been easily solved as well. At many roundabouts in the UK, pedestrian crossings are built underground (they call them 'subways'), allowing pedestrians to get from one side of the roundabout to the other without crossing vehicular traffic at all. I understand that our neighbors to the north, the City of Dublin, has implemented a number of these underground crossing for precisely this reason.

And on this point about money, please understand that articles you may read in the papers about the City of Hilliard and Hilliard City Schools arguing about money is simply this: there is a significant cost associated with this project, and the City of Hilliard wants to minimize its expenditure, and the less they have to spend on school stuff, the better it is for them. The City of Hilliard is getting a good chunk of money from the US Government to underwrite some of the cost, but not all.

The rest has to come from local taxpayers, either via the City through income taxes (paid by people who work in the City), or via the School District through property taxes (paid by everyone who owns property in the School District). Both entities want to preserve their tax revenue for other purposes, and get the other entity to pay for as much as possible.

Most of those costs have to do with the construction of the actual roundabouts. Other sizable amounts have to do with the changes that will have to be made to Hilliard City School facilities to accommodate and replace the property features that will be lost (e.g. the parking lot in front of Hilliard Station 6th Grade School). The conversations going on between the City and the School District have to do with how much those costs will be, and who should bear the cost.

It's just a negotiation, which is always a mixture of motivation and opinion – and sometimes a little emotion.
On Thursday, April 29, at 7pm in the Central Office Annex, you are invited to one of our Community Conversations to hear from and ask questions of representatives of all the municipal jurisdictions affecting our school district (Hilliard, Columbus, Dublin, and Franklin County). If you have questions or concerns about these roundabouts and other development plans in our community, this is a great opportunity to have them addressed.