A Snapshot of Things to Come

Scott en Aztlán wrote:
> Given the success of this speed camera experiment in Scottsdale,
> expect the idea to spread like wildfire very soon, probably to a road
> near you.
>
> http://www.azstarnet.com/sn/hourlyupdate/152418.php
>

<snip>

Something major was left out of the report.

What was the posted limit?

What was the 'flow' speed before installing the cameras and what now?
Not what a few at the top end were driving but the average (85%). I
have a feeling that they haven't changed the 'flow' all that much.

Would also be interesting to see a report listing time of day vs
tickets written. My bet is the high speed tickets all fell during
periods of sparse traffic where there would have been no problem with
the speed per se.

Harry K

The speed limit on Loop 101, including this section in Scottsdale, is
65. I think most of the traffic was doing at least 75 during non-peak
hours before the cameras were installed.

As far as urban freeway speed limits, I don't remember the year, but
many freeways went up to 65 from 55. Only portions of I-10, I-17, AZ
51, Loop 202 and AZ 143 have a 55 zone (all relatively close to central
and downtown Phoenix, or Sky Harbor Airport).

In article .com>, Harry K wrote:
> What was the posted limit?

It's not even relevant.

> What was the 'flow' speed before installing the cameras and what now?

Obviously it was roughly 76mph given that if 50% were exceding 76mph it
would be the mode. The mean and the mode are the same thing in an ideal
bell curve distribution. Now it's clearly much lower, and I doubt it's
neat bell curve distribution.

> Not what a few at the top end were driving but the average (85%). I
> have a feeling that they haven't changed the 'flow' all that much.

Since when is 50% 'a few at the top end'?

> Would also be interesting to see a report listing time of day vs
> tickets written. My bet is the high speed tickets all fell during
> periods of sparse traffic where there would have been no problem with
> the speed per se.

Of course they do. Even the camera can only revenue one person at a time.

Brent P wrote:
> In article .com>, Harry K wrote:
(snip for this comment...)
> Of course they do. Even the camera can only revenue one person at a time.

True, but the camera can do that more frequently than Rent-A-Barney in
his squad car.

Brent P wrote:
> In article .com>, Harry K wrote:

>> What was the 'flow' speed before installing the cameras and what now?

> Obviously it was roughly 76mph given that if 50% were exceding 76mph it
> would be the mode.

Usually, the 85th percentile is 5 to 7 mph above the 50th percentile.
That means that the 85th percentile speed was between 81 to 83 mph.

Brent P wrote:
>
> Of course they do. Even the camera can only revenue one person at a time.
>
One car at a time. The owner of the car gets the ticket, not the driver.