One other thing, which is related (or not): Has the project for the reconstruction of Stadium between Pauline and the State/RR bridges been delayed, put on hold, or cancelled altogether?
]]>Staff has confirmed that our required work has not been jeopardized although it is true that the City is now less able to meet special requests or discretionary counts.
We are in the process of replacing the lost counters to give the City more flexibility in this regard.
]]>I would like to make some remarks about the planning and design process for road and bridge projects. I need to know 5 pieces of information before I start a design: 1. The design year (Typically 20 years in the future), 2. The existing traffic volumes (car counts), 3. The projected traffic volumes for the design year, 4. The design speed for the project, and 5. The design vehicle.
The road is designed for the projected volume of traffic in the design year during the highest peak hour of travel. Loosely speaking, the peak hour is the daily rush hour, either morning or evening.
As a traffic engineer, a grade separation is always preferable to an at grade intersection. Yes, bridges are expensive to build and maintain. The reduced impacts to traffic delays, response times for emergency services and crash reduction is far superior to an at-grade crossing. Which would you rather have a faster EMS response time with the bridge or risk a person dying because the ambulance was stopped by the train. The Illinois toll way says every minute that a lane is closed results in 4-5 minutes of congestion.
In response to Mr. Whitaker’s comments about the statistical modeling, the $250,000 figure is an assumed cost to society because of a crash. When we are in a crash, we see the price to fix our vehicle. What we do not see is the price to society. Whenever there is a crash, there are “hidden” costs associated with the crash response that may not paid by the drivers, such as police, fire, ambulance, morgue. These are the obvious costs paid by the taxpayer. Less obvious are all of the costs associated with anybody who ever touches the crash report.
The crash modelling is a little bit out dated only because AASHTO will be publishing the Highway Safety Manual. It is my understanding that it will be published later this year. This manual will give a traffic engineer rigerously tested, research based models to predict the number of crashes that will occur at an intersection. The manual will also provide proven methods to analyze an intersection and suggest methods to reduce the number of crashes.
The Center for Disease Control says that highway fatalities are a national epidemic. Every year, approximately 44,000 people die on the roads of the US. More people die on the highways than people dying of a heart attack. If 44,000 people died of a contagious disease, there would be national outcry for the government to do something.
If I wewre living in Ann Arbor, I would be pressing my legislator to get the bridge rebuilt as soon as possible.
]]>Why not use real statistics for AARR/automobile incidents from the eleven at-grade crossings we already have in Ann Arbor instead of these statistical models (New Hampshire Index and Peabody-Dimmick)? I’m sure there must be an incident on the AARR line in Ann Arbor from time-to-time, but I’m having trouble recalling any.
The memo also uses a $19 million figure for replacement of the bridges and $22.3 million for the “societal costs.” The 2008-2013 capital improvements plan estimates the total cost of replacing the bridge over State at $9.2 million and the total cost of replacing the bridge over the AARR at $12.85 million, for a total of $22.05 million. (Credit to Karen Sidney for that info.) So, even if you accept remote cost-benefit analysis and traffic models, it is at worse, a break-even proposition. I’m sure the construction figures will only continue to go up. (And what about the fuel costs to detour around this area during construction of bridges…Broadway took two years, didn’t it?)
Ironically, I just met with an Ann Arbor traffic engineer the other day to observe traffic on a street near downtown. After remarking at the unexpected volume of traffic we were seeing, I asked if we couldn’t put one of those car-counter boxes in for a few days to get an accurate count. He said they had all burned up in a fire and the City hadn’t replaced them.
I guess we don’t need real data when one can sit in a cubicle and pull up online statistical models. Right?
]]>Mr. Nearing is a master of understatement.
]]>It also seems that they gave no consideration to the potential for a decrease in traffic in the future. One possible opportunity that could arise from such a scenario is that Stadium could be reduced to three lanes, rather than needing to be expanded to five to accommodate the at-grade intersection. That would likely lower the costs of the bridges (or the intersection and crossing), but it’s not clear how everything would balance out.
]]>In Plymouth on Sheldon road and M14, the at-grade RR crossing is being coverted to a bridge over the tracks because of all the backups and headaches that this crossing has had. If you have ever been stuck at this crossing when a train is passing, you literally can be stuck for 10-15 minutes.
Plymouth is upgrading to our present system; our system just needs a repair or replacement, but is probably the best solution according to the research in the memo.
]]>