This bridge has four creosoted 12x24" wooden beams as support. Some time in the past, the decking was all taken up and the two 12x24x½" steel I-beams were laid alongside the wooden beams. This bridge has stout support underneath.
I wish I had broken out the camera earlier when there was something interesting to see, but here's an image of the almost completed work:
Not shown are the many 2x10" and 2x12" runner planks that are now serving as treads so that vehicle tires don't exert pressure on any single cross timber.
All of this needed to be done to repair the bridge for my own use, but also because I am in bad need of having the steep part of the driveway repaired. The excavators who have already been paid to do the work refused to drive their equipment onto the property until the bridge was fixed, so I have been waiting for seven months to get this done. No more excuses, time to bring on the small caterpillar tractor and the roller machine. Time to be able to drive up to the house without locking in the front hubs on the 4x4.