The design for incorporating bikes would have to come down from the top.

As I mentioned, it appears as if Portland has two Amazon warehouses that are quite distant from the majority of the population, although there likely would still be some local population accessible by bike around the warehouses. Oh, Hillsboro is bigger than I thought.

One could probably do palatalized/containerized cargo for bikes. So, fill the bike containers at the warehouse, then load them into a truck, and head off... then just load the containers directly onto the bikes. The transfer could be quick and efficient.

One could even design the cargo containers to contain a battery for e-bikes. Recharge at the warehouse, then when one loads the bikes, they also get fresh batteries.

Even at the warehouse, load up the containers while the bikes are buzzing around, then when they return, drop the empty container and snag a full one for the next delivery.

I could imagine an agreement with a local shopping mall for off-peak access to the parking lot. Roll the truck into the parking lot. Offload onto bikes like little worker bees, and send them out. Then take the truck to either the next destination, or back to the warehouse to refill.

Everything would have to be above board, but it could be made to work.

And, might be good PR for Amazon, especially in so-called bike cities like Portland.