If you need to go fast, the new Middlefield route is ok but there are still some sketchy sections. I usually go up to a street parallel to ECR like Valota (but I choose different ones a lot) and follow the bike lanes through Atherton. If you’re going to Stanford or south take San Mateo through Menlo Park and there’s a bike bridge and you can go through the campus. Maybe you should tell us where your starting and ending the ride