I don't know the northside very well and was curious as to whether anyone had a direct, relatively traffic-light route from the city (cross into the northside from any of the 3 Sisters Bridges) to Riverview Park? Thanks!
Here's one I've done a couple times... nice ride. Another time I took Brighton back to the N. Side which isn't bad but adds a little extra climbing. I keep meaning to go back on 19 but I like the descent on Riverview Dr. too much 
http://www.gmap-pedometer.com/?r=3059111
BTW, you can ignore the part that goes through Manchester, I wanted to see where the "official" detour went but now the trail is fully re-opened.
Depends on what part of Riverview Park you are heading for....
You can get to the bottom of Riverview Park by following the North Shore trail around the Stadiums, past the casino, and out to the Western Pen (the end of the trail). Just before the prison, take Doerr Street inland one block. Take a left on Beaver Avenue, and a right at the next street onto Eckert. This will take you UNDER Route 65. Staying to the right when the road V's (near a small bar) will take you onto McClure, which in turn will take you onto Woods Run. Staying on Woods Run will take you to a short but steep section on Mairdale. If you stay left on Mairdale it will take you to the north end of the Park, on top -- near Semicir.
The other option is to turn right off of Woods Run onto Central, which then turns into Grand and then into Kilbuck Street. This is the bottom of Riverview Park. There are trails that will connect you to Riverview Avenue at the top, but I am not confident enough to be able to give you those directions via bb.
Once you leave the trail on the North Side, I suspect you'll see very few cars until you get to Mairdale, which is something of a local connector.
"... right off of Woods Run onto Central ... Grand ... Kilbuck Street ... trails that will connect you to Riverview Avenue at the top...."
If you've found your way to Kilbuck, then you've done the part that's hardest to navigate. From there it's just uphill at every point. The trail is mostly pavement actually.
The intersection at Woods Run and Central is sort of easy to miss unless you are looking for it. It has a fire house at the corner.....
Thanks for the advice everyone! Connecting from the bike trail to the bottom of the park was my difficulty. This helped out.
The secret is getting through the tunnel, and then staying low until you get to Central.
