🚀 go-pugleaf

"Douglas A. Willinger" <dougwill@idt.net> wrote:
> 
> Scott M. Kozel wrote in message <36C637AC.276A@richmond.infi.net>...
> >cpatz@ibm.net (C. P. Zilliacus) wrote:
> 
> >The 22-mile Virginia side was 65 mph, the Woodrow Wilson Bridge was 60
> >mph, the 30 miles from MD 210 Indian Head Highway to MD 97 Georgia
> >Avenue was 70 mph, the winding section through Rock Creek Park was 50
> >mph, and thence to the Cabin John Bridge and across to Virginia was 60
> >mph.  These speed limits seemed to match the design speed of the
> >highway, based on horizontal and vertical curvature, and stopping sight
> >distance.
> 
> As well as the average vehicle of the time, some one third of a century ago-
> given the advancements automobiles in general regarding their tires. brakes
> and suspensions.  Up to a certain point of traffic density, you can add 5-15
> mph to the above pre-1973/4 speeds, as attested by the 60-70 mph traffic
> speeds along the curvy sections of the Capital Beltway between Georgia
> Avenue and Wisconsin Avenue, and 65-80 mph elsewhere.

Yes, but traffic volumes on the Beltway have tripled since then.  It now
carries volumes ranging from 190,000 to 225,000 vehicles per day. 
Hence, a 55 to 60 mph speed limit today is appropriate.
 
-- 
Scott M. Kozel     Highway and Transportation History Websites
Virginia/Maryland/Washington D.C. http://www.richmond.infi.net/~kozelsm
Philadelphia and Delaware Valley
http://www.geocities.com/CollegePark/Campus/5961/pennways.html