You can follow the River Lea from the Thames (opposite bank to the Dome) all the way up to Hertford without needing to encounter any traffic. It gets a bit busy with walkers, especially around the Olympic Park, but much of the surface has recently been upgraded for the Games. Makes a nice long stretch if you want to stay off road and don't mind mixing it with walkers. It's quite pretty in places too, especially around Ware.
You can follow the River Lea from the Thames (opposite bank to the Dome) all the way up to Hertford without needing to encounter any traffic. It gets a bit busy with walkers, especially around the Olympic Park, but much of the surface has recently been upgraded for the Games. Makes a nice long stretch if you want to stay off road and don't mind mixing it with walkers. It's quite pretty in places too, especially around Ware.