This morning on WNYC Brian Lehrer said he didn’t understand why Mayor de Blasio would want to penalize Uber for making traffic congestion worse, since the mayor is “causing congestion purposely” to make streets safer for walking and biking.

Here’s an excerpt:

They want to make driving in the city as unpalatable as possible so people switch to mass transit, which is more in the public interest for a host of reasons. And I tend to support that, that’s a good idea. Also the de Blasio administration has made Vision Zero a central policy — something else I support. But again the goal is to make traffic go slower, not to make it easier on cars. They’ve reduced the official speed limit too. And congestion accomplishes the same goal — that is, fewer pedestrian fatalities — by other means. Traffic means less speed, which means more pedestrian safety.

Like a lot of people who weighed in during the Uber debate, Lehrer confuses speed limits and average speeds.

Lowering the maximum speed people are allowed to drive has nothing to do with a grinding crush of cars inching along at a few miles per hour. An easy way to grasp the difference: The citywide speed limit is 25 miles per hour, while last year the average speed in the Manhattan core was 8.51 mph. Congestion is a symptom of too many motorists trying to use scarce street space at the same time, not a tactic to make drivers travel at a safe speed.

Put another way, in the early 1980s motor vehicle traffic was moving at an average speed of 9.8 mph on midtown avenues and 6.4 mph on crosstown streets. Though congestion was about the same as it is now, more than twice as many people were dying in traffic.

Lehrer also said taking cars out of Central Park was de Blasio’s way of creating congestion on the avenues. Instead of propagating tabloid-worthy conspiracy theories, we liked it better when Lehrer was calling for “bike lanes everywhere, separated from traffic.”