I heard back from the Greenway folks. That was fast! This was forwarded to me by Michael Oliva, the Mid Atlantic Trail Coordinator for the East Coast Greenway Alliance, and shared here with his enthusiastic permission:
The bridge has a wooden walkway which is currently open to cyclists . For the safety of pedestrians and cyclists alike, cyclists are required to walk their bikes across. The rehabilitation project for the bridge is in its planning stages with the expectation that construction activities will commence in Spring of 2010. I’ll be able to communicate better as we get closer to that time frame what impact the construction will have on foot/ cycle/car traffic across the bridge.
I should also note that as part of the planning process, the DRJTBC will be reaching out to stakeholders on both sides of the river to secure their input and use that information to assist in planning the construction activities.
Your correspondent apparently refers to construction going on at the Trenton Water Works north of the bridge which is using the lower end of the Riverside Park as a staging area. The route they ended up taking on city streets is the only way I know of to approach from the north. It is , as they mention, an overpass type access with an alternate vehicle merge for traffic from the south, Calhoun (Martin Luther King Blvd. and the north at the bridge entrance. If the cyclist is uncomfortable with the roadway, there is a sidewalk for the short approach to the bridge.