Alternatives to trailers for transporting young children A representative in Oregon has recently introduced a bill that would prohibit children under the age of six from riding in bicycle trailers. While it is far too early to tell whether this bill will pass, and what the final law would look like if it did, I am curious what alternatives to bike trailers people can recommend. I don't have kids myself, but I grew up riding around in a bike trailer, and know people who do have children and use trailers like these. I am particularly interested in suggestions for families with multiple young children, since one reason my family loved bike trailers was because it could easily fit two of us at once. If this law were to pass, what alternatives would be available?
Followed some links from your links and found the actual text of the law, which summarizes the law as:


  Prohibits person from carrying child
  under six years of age on bicycle or
  in bicycle trailer.


Elsewhere in Oregon law, a bicycle is defined as:


  [a human-powered vehicle] designed to travel with not more than three wheels in contact with the ground. 


So a unicycle, bicycle and tricycle are all covered by the proposed law.  There's also a wheel-size provision in the definition, which makes me suspect that too small of wheels or 4 of them puts you in a category like skateboards that probably aren't allowed on the road.

So I think you simply have no solution if that law passes as written. Everything I've ever seen for using a bicycle to transport a child constitutes "on bicycle" or "in trailer".  Even if you devised some clever sidecar or push-cart mechanism to get around the letter of the law, I doubt that would work.

But just in case it's useful, there was an earlier question along these lines that I think covers all the answers you could be looking for: Recommendations for Transporting Twins On The Front of a Bike

Basic summary:


Coolest option is a bucket bike (long wheelbase with a big box built in). Common in Netherlands, rare in the US.  Search for "cargo bike" in your area (I know there's bikes of this type made in Portland, OR)
Next best is probably a long-tailed bike, such as an extracycle, especially if you can get seats designed for that use
There's child seats that mount on a bike rack behind you
child seats that mount on the handlebars in front of you (you could combine this one with any of the other options)
Trailers are pretty darned good for carrying children.