Whenever you’ve got to close a street or a bridge to make repairs it’s going to have a ripple effect on surrounding traffic. That’s what detour planning is all about. Obviously if you’re repairing something for safety reasons the last thing you want to do is create a safety hazard while you’re trying to make something else safer. I know it looks like detouring means hanging a few orange signs around but there’s actually a surprising amount of advance planning and engineering analysis that goes into detouring. It’s true that most of the times detours can be handled with a few well placed signs but other times the City has a whole series of action steps planned with contingency plans ready to kick in if the initial efforts need some back up. That’s exactly what’s going on with Spaulding Drive bridge repair which is getting ready to begin this summer.
The Spaulding Drive bridge over Fishcreek can easily go unnoticed as a bridge since it is a comparatively smaller structure that is mostly out of the site of the driver and with the exception of the hand-rails there’s no real change in the road to make you realize you’re even going over a bridge. Appearances can be deceiving though and it is still a bridge that is in need of repair.
As a matter of fact, earlier this month we posted a lower weight limit on the bridge as a precaution against excess loading given the weakened state of the bridge right now. The reduction only affected very heavy trucks, e.g., trash trucks and concrete trucks, but it’s evidence that this structure is reaching the end of its safe service life.
With bridge repairs imminent the staff has been working on how to deal with the traffic issues resulting from the temporary bridge closure. Obviously the folks that live over in the Silver Meadows neighborhood rely on Spaulding Drive to get to SR 59 and for the next 8 months they will have to make a much more round-about trip using Fairchild Avenue. Not only is that inconvenient it is a safety concern based on ingress/egress at the already challenging Silver Meadows/Fairchild Avenue intersection.
The City’s Engineering staff have been busy making plans and communicating with residents in this neighborhood in anticipation of the bridge closure. Here’s a summary of the action that they’ve been working on:
– The issue was taken to the Traffic Engineering and Safety Committee to recommend an appropriate plan of action
– The road is anticipated to be closed during the summer vacation for Kent City Schools
– Traffic data was collected in February 2009 to get a baseline view of traffic at the intersection
– Traffic will be monitored after the detour is initiated. This will be done at least one week after the closure to allow motorists to adjust their daily commute to the detour.
– Based on the amount of traffic increase or decrease and the additional delays incurred at the intersection we will determine if the increase needs addressed
– To address any detrimental increase in delays and congestion we included in the construction plans a requirement to have police officers at the intersection to direct traffic at peak hours of the day. This would be done at an additional cost to the City.
– A number of residents in that area have also requested a signal be constructed at the intersection to address the issue. Installation of a traffic signal requires a traffic study to “Warrant” a signal. This would not be done for temporary traffic conditions, but for typical traffic conditions at the intersection. No recent warrant analysis has been done for this intersection. Lastly, if the intersection “warrants” a signal, that does not mean one has to be installed. The project (construction of a signal) would be added to the list of needs within the City and prioritized based on safety, traffic congestion and cost. A typical mast arm signal would cost appx. $200,000 to design and install.
In the end, traffic engineering is as much a social science as it is a hard science so even though we’ve got some good hard data that is guiding our planning process we will have to wait and see how drivers handle the changes. Usually the best detour plans follow the KISS principle of keeping it simple. Truthfully, the fewest changes possible is always safer because motorists tend to creatures of habit and the fewer the surprises the better. But that being said our goal is still safety and if we see something in the plan is not working we will react quickly and decisively.