Subject: When Ohio 835 went from 35mph to 50mph:

From: [email-masked] (Kevin Atkinson)
Date: 6 Aug 1995 19:12:24 -0400

Kenny Morse:

Here is another study that proves first hand that people do not 
automatically go 10-15 mph above the limit.  Notice how people barely
changed their speeds when the limit went up.

(This and other stuff can be found at my Reasonable Drivers Unanimous at
 http://www.clark.net/pub/kevina/sl/)

SPEED INVESTIGATION OF OHIO ROUTE 835 IN THE CITY OF BEAVERCREEK 1992-1993

by Duke P. Ganote, P.E. (touched up by Kevin Atkinson)
May 27, 1993

SUMMARY 
As I discussed in the newsletter first posted in this topic, the posted speed
limit on Ohio 835 is now 50-mph [it use to be 35-mph].

Using a radar gun, I collected five sample of "before" speed data. I'm in the
process of collecting five samples of "after." The "before" and the to-date
"after" data is presented next.

DATA SUMMARY
[I] took eight (8) bidirectional spot speed samples of 200 vehicles each on
the mainline section of SR 835. Samples were taken under favorable
conditions: dry pavement, temperature from mid-50s to 70s (F), overcast to
sunny weather, and no permanent enforcement presence. Summary data is shown
below.

SPEED               BEFORE [1]             AFTER [2]

STATISTICS  ______________________________   _____

90th%tile (mph)   57   55   58   55   56      57   56  58

85th%tile (mph)   55   54   55   54   54      56   55  56

67th%tile (mph)   52   50   51   50   49      53   52  53

50th%tile (mph)   49   48   49   47   48      49   50  51

15th%tile (mph)   43   43   42   42   42      45   44  46

Pace [3]   (mph)  53.0 53.0 52.5 52.0 53.0  54.0 56.5 55.0

% in Pace         57.5 66.0 59.0 63.5 63.0  67.0 70.5 71.0

Mean (mph)        49.3 48.3 48.9 47.8 48.0  50.1 50.4 51.0

% exceeding 65mph  1.5  0.5  1.0  1.0  1.5  1.0  0.5  2.0

% exceeding 60mph  5.5  2.5  5.0  2.5  3.0  4.0  3.0  6.0

% exceeding 55mph 15.0  8.5 12.5  9.5 13.0 15.5 14.0  15.5

% exceeding 50mph 43.0 31.0 36.5 27.5 28.5 44.0 46.0  50.5

% exceeding 45mph 68.5 66.0 66.5 62.0 62.5 81.0 81.5  86.5

% exceeding 40mph 94.0 91.0 92.0 88.5 88.0 95.5 97.0  99.0

% exceeding 35mph100.0100.0 99.5 98.5 99.0 99.0 100. 100.

[1] April 22, May 3 & 16, June 10 & 20, 1992

[2] May 9, 13 & 27, 1993 

[3] Upper limit of 10-mph pace (10-mph grouping with
     largest number of vehicles).

My preliminary conclusion:  speeds may have increased 1- or 2-mph since the
posted limit was changed from 35-mph to 50-mph. Most of the increase seems to
be due to slower drivers getting "up to speed" and into the pace (the
percentage of drivers in the pace is up from about 60% to about 70%).

-- 
* Kevin Atkinson, Clarknet I'net Serv., Maintainer of the Usenet Info Center *
*     Finger [email-masked] for more info on Usenet Info Center.         *
*    Or send mail to [email-masked]  with a subject line of HELP.        *
*  This is in its beginning stages and I could use any help I could get!     *