Archived posting to the Leica Users Group, 2003/03/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 9:19 PM -0500 3/9/03, Marc James Small wrote: >At 05:49 PM 3/9/03 -0800, Martin Howard wrote: >> >>I think these are both German inventions, with the advent of the first >>Autobahn. The separation of traffic flows via a median, an overtake >>lane (a concept lost on most US drivers), and on and off ramps are all >>Autobahn firsts, AFAIK, although in the US, the concept was extended >>upon (particularly through spaghetti interchanges) when the Interstate >>system was built. > >Martin > >The Pennsylvania Turnpike was the first divided-lane high-speed road ever >built, dating from a decade before the Autobahns were conceived. This road >came equipped was all of the attributes you discuss. By the time the first >Autobahn was constructed, there were probably 25,000 miles of such roads in >the US. > >Marc > >msmall@infi.net FAX: +276/343-7315 >Cha robh bąs fir gun ghrąs fir! The Autobahn in Germany got its start with the establishment of an organization in 1926 called HaFraBa for 'Hamburg - Frankfurt - Basel' who's purpose was to build a road for high speed traffic between those cities. The inspiration came largely from the earlier (1924) Autostrada from Milano to the Lombardy lakes. The Italiens built a number of high speed roads with few curves and no level crossings, but at that time not divided. The German Autobahnen as constructed in the early thirties were divided as well, and had travel plus passing lanes and interchanges that foreshadowed the spaghetti interchanges. For some strange reason the Italians didn't combine Autostradas and spaghetti as readily :-). The Pennsylvania turnpike as a divided high speed road didn't arrive until 1940, although it originated as an idea for a railroad by Vanderbilt, but it never turned into a success and it was largely abandoned, with many tunnels bored. In the 1930's some people saw the right of way and the tunnels as a basis for a high speed road. I believe it was originally intended to be just one lane in each direction, undivided, due to the size of the bores drilled for the railroad, but was expanded to 4 lanes when it opened in 1940. As in most things, there was not one 'inventor', but a gradual development, and each development was adjusted to circumstances as existed in each country at the time. America developed the 12 lane highway with on-ramps and exits from both sides (which are not tolerated in Europe) and Germany developed the present Autobahn which (if it is ever clear enough of traffic) is suitable for 250km/hr speeds with a higher traffic density than in America. Neither is superior; they are just different. - -- * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html