Now that the county and the township have begun the project that will result in the rebuilding of the Cranbury Road bridge over Big Bear Brook, it’s a good time to stand back and see what has happened so far.

Several weeks ago, I reviewed the most important aspects of the traffic situation and how it might be affected. The most impressive thing at this point is the installation of the traffic signals at the intersection of Cranbury and Clarksville roads.

They have not been activated, and they just sit there waiting, but once they become needed, they should attract attention. It’s as if Grovers Mill will finally qualify to join the world of real traffic, automobile, that is.

In the morning, when traffic is heavy on the way to Princeton Junction station, the lights will undoubtedly affect the flow for a while, but right now, the traffic must handle conditions without them.

With the bridge closed, there will be no traffic going along Cranbury Road from Grovers Mill all the way to the station and back, nor will there be any traffic there from Plainsboro via Millstone Road.

I should say that there will be the traffic from Princeton-Hightstown Road (Route 571) on the west and from Millstone Road on the east just up to the bridge to allow people who live on those sections of Cranbury Road to reach their houses.

And, of course, through traffic that must go to the station using the western portion of Cranbury Road with the bridge will be impossible. All traffic to the station that must go from points east of the bridge will have to use Clarksville Road and Route 571.

Since I live close to the intersection of Clarksville and Cranbury roads, I have had the opportunity to speak to some of the people working on the installation of the traffic lights. At this point, I am convinced that they are aware of the difficulties with the installation and of the problems that will be created for drivers.

In fact, just to emphasize this fact, a temporary barrier that had been erected across west-bound Cranbury Road was removed because, as I pointed out, it was not needed to keep west-bound traffic off of Cranbury Road beyond Millstone Road. Hopefully it will stay that way until the bridge is finished.

So for a bridge that was built in 1986, why does it need to be replaced? There must be something seriously wrong with it.

Is it about to fall down if it’s not repaired? Well, according to the Mercer County Department of Transportation, the bridge is in poor condition due to substructure defects. It is categorized as structurally deficient with a rating of 48.2 on a scale of 0 to 100.

That seems to be pretty bad, although does anyone really know how long it would continue to serve the purpose if left as it is? Probably not. But the best thing is to go ahead and fix it before something bad happens.

The new bridge will have two spans to reach across the Big Bear Brook at this point. (I should note that West Windsor also has a “Little” Bear Brook. But it’s located farther north and west than the “Big” one, and is much smaller in terms of how much water it carries.

In fact at certain times of the year its flow actually reverses direction and it carries water away from the Millstone River.

But “Big” Bear Brook always flows into the Millstone and under the Cranbury Road bridge. Little Bear Brook can be seen where it flows under Alexander Road a bit north of Vaughn Drive.

The new bridge on Cranbury Road will be the second one to be built in recent memory. In 1999, a replacement was built for the one over the Millstone River at the border with Plainsboro.

That itself was a replacement for one of the really old ones with pipe side rails that had stood for many decades. A short portion of the old roadway that was part of that bridge is still there and serves as an entryway for a nearby private driveway.

Not far from that location is a really old supporting structure for what at one time was an interurban rail system the connected Trenton and New Brunswick. The supporting structure cannot be seen from the present road.

I saw it a couple of decades ago from a canoe on the Millstone River. That was in the days when “Friends of West Windsor Open Space” was just getting started.