TAN: Speed Limits (was Ten Items or Less at Trader Joe's In Sunnyvale)

On Wed, 24 May 2006 22:45:02 -0700, Scott en Aztlán
> wrote:

>[Followups on this tangential thread redirected to rec.autos.driving]
>
>On Wed, 24 May 2006 04:36:54 +0000 (UTC), (Don
>Klipstein) wrote:
>
>> How about I dare to comment on speed limits where I see significant
>>diversity on two similar roads and an interstate highway stretch having
>>its limit recently raised by 10 MPH:
>
>My general view on speed limits is that they should be set
>scientifically by engineers, not politically by money-grubbing
>municipal governments. The 85th percentile speed is the scientifically
>accepted standard for setting speed limits; if this method is used,
>then I support the limit that is posted.
>
>> Route 73 from "Broad Axe" to about a mile southeastward has a posted
>>speed limit of 50 MPH, and that posted limit is well-obeyed.
>
>Properly-set speed limits usually are.
>
>> The road crossing 73 in "Broad Axe" from SW to NE is "Butler Pike".
>>
>> Butler Pike from Germantown Pike (about 3 miles SE of "Broad Axe")
>>to a good half a mile NE of "Broad Axe" surely appears similar enough to
>>the 50-MPH-posted portion of Rte. 73 in that area!
>>
>> BUT... Butler Pike has a few houses close enough to the road for that
>>road to be legally in PA a "residential street" as opposed to a "country
>>road" and therefore subject to a statewide government mandate of a
>>speed limit of 35 MPH for such technical classification of a state
>>highway.
>>
>> And for how fast traffic moves on that stretch of Butler Pike? most
>>vehicles there get well into the 40's MPH, often 45-50.
>
>And that's what happens when you set speed limits politically rather
>than scientifically - low compliance.
>
>>2. How about the stretch of the "Northeast Extension" of the "PA
>>Turnpike" in its most-south segment, between "midcounty interchange" and
>>"Lansdale"? Sometime within the past couple years the posted limit on
>>that stretch of that highway went up from 55 to 65 MPH.
>> I did notice that median speed and speeds of all percentiles above maybe
>>20th percentile increased maybe 1 MPH - as in obeyed the new higher limit
>>more closely by 9 MPH after the limit was increased by 10 MPH.
>
>So you're saying that people who drove at 65 when the SL was 55 now
>drive at 74? If so, the SL is still too low. My bet is the 85th
>percentile speed is around 75 - 80 MPH.
>
>>Slower vehicles as a result sped up enough to improve speed consistency.
>
>Clearly a good thing!
>
>> In fact, my personal top speed record in the right lane of that stretch
>>of road and sustained for a mile occurred when the posted limit in that
>>stretch of that road was 55 MPH, and I did not go any faster (peak nor
>>average for a month nor for a year) in that stretch of that road not even
>>by 1 MPH after the posted speed limit there was increased by 10 MPH.
>
>This is starting to sound like a word problem.
>
>So you're saying you normally drive at the 85th percentile speed for
>that stretch of road, and that raising the limit didn't affect your
>typical speeds at all?


On the other hand, it could mean that 85% of the drivers on that
stretch of highway are idiots.

Around 5/25/2006 4:27 PM, Bob Ward wrote:

> On Wed, 24 May 2006 22:45:02 -0700, Scott en Aztlán
> > wrote:
>
>> [Followups on this tangential thread redirected to rec.autos.driving]
>>
>> On Wed, 24 May 2006 04:36:54 +0000 (UTC), (Don
>> Klipstein) wrote:
>>
>>> Slower vehicles as a result sped up enough to improve speed consistency.
>>
>> Clearly a good thing!
>>
>>> In fact, my personal top speed record in the right lane of that stretch
>>> of road and sustained for a mile occurred when the posted limit in that
>>> stretch of that road was 55 MPH, and I did not go any faster (peak nor
>>> average for a month nor for a year) in that stretch of that road not even
>>> by 1 MPH after the posted speed limit there was increased by 10 MPH.
>>
>> This is starting to sound like a word problem.
>>
>> So you're saying you normally drive at the 85th percentile speed for
>> that stretch of road, and that raising the limit didn't affect your
>> typical speeds at all?
>
>
> On the other hand, it could mean that 85% of the drivers on that
> stretch of highway are idiots.

But who cares, as long as they're safe idiots?

Remember, one of the criteria of the 85th percentile method (aside from
the obvious) is that there should be no unusual pattern of collisions to
justify a lower limit.



--
~/Garth |"I believe that it is better to tell the truth than a lie.
Almgren | I believe it is better to be free than to be a slave.
******* | And I believe it is better to know than to be ignorant."
for secure mail info) --H.L. Mencken (1880-1956)