Some of you may have heard of "ciclovia", the car-free street events that originated in Bogota, Colombia. In Portland, Oregon, they're known as "Sunday Parkways" and they've been a hit there since the first one in 2008.
Sunday Parkways take place at various locations throughout Portland about once a month, and involve closing off a loop of ~10km of streets for 5 hrs so that people can walk, ride, scoot, skate, whatever without the distraction of motor traffic (yes, if you're a local you can still access your house, although they encourage you not to drive if you can avoid it).
Unlike many ciclovia, where main roads are closed down, Portland has opted to close off mostly local streets, including some routes along its "bike boulevards". Where the route crosses main streets, Police are used to alternate priority between the parkway and main-street traffic.
At parks along the route various stands, food-stalls and events are set up. These include live music, bike maintenance, sports games, eco-lifestyle information, demonstrations/trials of interesting bikes, and numerous give-aways.
Many enterprising local residents also join in the fun with their own lemonade stands, garage sales, or sprinklers to ride through (much needed on a hot day!).
All in all, tens of thousands of Portlanders come along for a very fun day - and apparently are always asking when the next one is.
Is it time to hold one in your town? The link at the top to Portland's Sunday Parkways also includes some very useful background documentation from planning the first two years of events there. Needless to say, it is potentially a big event requiring considerable resources and support from Council, Police and other agencies, as well as a small army of volunteers.