"When I was a kid, I biked in the street and it was no problem"

I'm not sure when and where you were a kid, but the conditions on the streets today vs. 30 years ago or even 10 years ago are very different (attached is a picture of Santa Cruz Avenue of yesteryear, perhaps from the '60s):

• Huge increase in the volume of traffic. We live in the middle of the Silicon Valley and the great economic boom to our area has been met with a huge influx of commuters passing through our city. 80% of traffic in Menlo Park neither starts or ends in Menlo Park.
• Wayfinding apps like Waze have brought cut through commuters into our neighborhoods. Unlike those who live here, cut through commuters are less invested in the quality of life in our community and are mainly concerned with shaving precious minutes off their commutes. This may lead to more risky driving behaviors.
• Increase in distracted driving brought on by cell phones (texting while driving). Yes, we need to work on enforcement and modifying bad behavior, but we must also design our infrastructure keeping human nature in mind.
• More families drive their kids to school vs. allowing them to walk/bike. In 1969 about 50% of kids walked and biked to school. In 2009 it was 13%. This can be blamed on an increased awareness/paranoia about stranger danger, poor land planning that put schools farther away from families, the rise of dual earner families with less time to walk/bike their kids to school, an over-reliance on cars, and more. Whatever the exact reason is, the result has been an influx of peak-hour traffic - nationally school-related commuting is 10-14% of morning traffic (likely more in our area). The increased traffic means more cars, which means worse biking conditions, which means more chose to drive, and so on.

All of these conditions have created a very scary and stressful situation for those wanting (and needing) to bike and walk. Asking cyclists to "share the road" with huge minivans and SUV's, traveling at 35 miles per hour, is not acceptable. This chart shows the injury/death rate of collisions with vehicles at different speeds. When cars and bikes/peds meet, much of the time it doesn't end well for those walking or biking.