Civil Engineering: Traffic Problems in History

All roads lead to Rome . . .

 The Romans built a huge network of roads. They were primarily for military use, but also used for trade. In all, the Romans built over 50,000 miles of hard-surfaced roadway.

Before the roads were paved, the weather could slow down any kind of travel. Rain could wash away sections of road, flood areas, or turn highways into mud bogs after many feet trampled the soggy path.

In those days, you had to walk most places – imagine getting your best pair of Corinthian leather Birkenstocks stuck in a mud hole halfway from home!

"Where we're going, we don't need roads . . ."

In Italy, the engineers developed a form of concrete, made from volcanic ash and lime. They used this to build roads that were strong, straight, and cambered, to allow the rain to run off.

In Pompeii, the roads had other “modern” designs built in. They had crosswalks that were raised, so pedestrians could stay out of the mud. They also used white stones as reflectors, placed at regular intervals down the center of the road. These were bright enough to catch the light from the carriages.

That's a raised crosswalk, so pedestrians didn't have to walk in the dirty streets.
The wagon and chariot wheels were standard widths, so they could pass between the gaps in the stone.

A cross section of Roman street design, from:  A Dictionary of Greek and Roman Antiquities. London: J. Murray.

The general appearance of such a metalled road and footway is shown in an existing street of Pompeii.
(A). Native earth, levelled and, if necessary, rammed tight.
(B). Statumen: stones of a size to fill the hand.
(C). Audits: rubble or concrete of broken stones and lime.
(D). Nucleus: kernel or bedding of fine cement made of pounded potshards and lime.
(E). Dorsum or agger viae: the elliptical surface or crown of the road (media stratae eminentia) made of polygonal blocks of silex (basaltic lava) or rectangular blocks of saxum qitadratum (travertine, peperino, or other stone of the country). The upper surface was designed to cast off rain or water like the shell of a tortoise. The lower surfaces of the separate stones, here shown as flat, were sometimes cut to a point or edge in order to grasp the nucleus, or next layer, more firmly.
(F). Crepido, margo or semita: raised footway, or sidewalk, on each side of the via.
(G). Umbones or edge-stones.

Today most of the top layer of concrete has eroded, leaving the bumpy looking pavers on top, but at the time, these roads were smooth and fast.

Civil Engineering through history, Part II

Flushed with Pride

www.hea-inc.com
As I speak, two of the three toilets in our building are out of service. Apparently there was a recall on the flushing system in our toilets that could cause pressure to build up in the tanks, causing explosions resulting in serious injury from the porcelain shrapnel.

No, seriously! I really wish I was clever enough to make something like that up.
 
So this week, the theme is on civil engineers' contributions to waste disposal.

Most of us have had the opportunity to visit an outhouse, usually at some Forest Service campground. I always imagined that was the standard fare for people around the world until the 1880’s, when Thomas Crapper made the modern flush toilet a household name, so to speak.

As it turns out, the bronze-age civilization of the Indus Valley Civilization had a flush-toilet in almost every house, with sophisticated city sewer system to carry it all away! (1)

But the Romans really ran with the idea, and developed a standard for waste-water management. They designed and built the Cloaca Maxima (Greatest Sewer) around 600 BC to drain the marshes and clear waste. It remains one of the best known sanitation artifacts of the ancient world. (2) 

If anyone knows where I can visit the museum of sanitation artifacts, I need a date idea for my anniversary.

Pictured: Sanitation Artifact of the Modern World

The wealthy citizens of Rome had toilets at their own homes around 100 AD, with public toilets available for the poor. Most of the time the poor used “chamberpots,” which they emptied by throwing the contents out of a window into the street. Sometimes they even looked to see if anybody was likely to be doused.  It became such a problem that fines were imposed if a person was “injured” by the debris!

Just imagine trying to explain where you got that black eye!

 In his Natural History, Pliny remarked that of all the things Romans had accomplished, the sewers were "the most noteworthy things of all".

That's right. Score one for Civil Engineers.

((1) Rodda, J. C. and Ubertini, Lucio (2004). The Basis of Civilization - Water Science? pg 161. International Association of Hydrological Sciences (International Association of Hydrological Sciences Press 2004).

(2(2)  Waters of Rome Journal - 4 - Hopkins.indd