Anonymous wrote:At that age, a bike seat on each bike might be easier/less bulky. But you'd have to check with school to make sure you can leave the trailer - probably hitched up to a bike rack. You will want a helmet - they have toddler helmets you can easily get. We got the CoPilot seat - really like it. As for trailers, Burley is one of the more popular ones, but it is very heavy, and while it can work as a stroller, too, it really isn't designed that way. Schwinn makes a great one that works beautifully as a stroller (so you can always bike there, stroller home). Baby Jogger makes a City trailer/stroller that also works really well as both a trailer and a stroller, but it is pricier than the Schwinn. We ended up getting the Schwinn...about a month before they came out with the City. It has held up quite well over the years.
This bike seat will be the best option because it is rated to a really high weight- 77 pounds. That means you will easily be able to use it for the next 3-4 years if you want. Two of them would be $350. You would probably want to get a basic rack for each bike, those are probably around $30-40 each
http://www.amazon.com/Bobike-Junior-Rear-Child-Seat/dp/B008Y5UMTW/ref=sr_1_2?ie=UTF8&qid=1429406757&sr=8-2&keywords=bobike
I am a daily biker and would heavily recommend biking as the way to get around. It is sooooo much faster than any other way at rush hour for distances less than 3 miles or so.
BicycleSpace is a great shop and I would go there first to see what they have for you.