Misread the poll and hit 3-4 miles. It's a hair under or over four miles (edited to add: each way), depending on the route I take (http://www.bikely.com/maps/bike-path/My-commute309730 says 6.1km, but there are loads of ways of making it ever so slightly longer).

It's about as far as you can go in a straightish line and not leave the city, though!