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.

Traffic Engineering: Saving the world one turn lane at a time.

www.hea-inc.com
Hardey Engineering and Assoc.

“You hit the brakes for a second, just tap them on the freeway, you can literally track the ripple effect of that action across a two-hundred-mile stretch of road, because traffic has a memory. It’s amazing. It’s like a living organism.” - Ethan Hunt (Tom Cruise), in his cover job as a traffic engineer in Mission: Impossible III.

I had to laugh as I heard this line in the movie. So many times while on a traffic count I had let my imagination run away with me. Instead of sitting in my truck for a 4 hours on a  grueling count of a suburban intersection, I was on stakeout. The placard in the window stating "Traffic Count in Progress" and the phone number of my employer, Hardey Engineering, were fake, a cover to distract passers-by.

It had to be more interesting that punching buttons on a glorified calculator, recording a sampling of left turns.

While watching "The Bourne Legacy" I had another flashback: sitting in front of two TV monitors with a cold pizza, watching a pre-recorded pair of intersections, tracking which cars passed through both, running the tapes back and forth.  In the movie, there were some grunt investigators doing the same thing to the traffic cameras, searching for the suspect's car.

Traffic Engineering: it's the perfect cover!

That's a Radar-gun.

Why?
Very few people actually know what it is.

Traffic Engineering is a unique blend of pairing the applied science of Engineering to the human decision-making process.  Not only do we predict present and future behavior, then we apply that flow to the roads and streets, to head off future problems.

Like water systems, traffic systems can only handle so many cars, and when that hits the maximum capacity, we get gridlock, accidents, and road rage.

Our job is to determine how much the system can handle, and how to improve the capacity. One of the tools we use is a traffic modeling simulator.

Like SimCity Traffic, but more math, and lamer graphics. 

Are you building a new subdivision? Do you need approval? We can tell you how many vehicle trips you'll generate,  how to make sure the neighborhood stays safe, and how to keep the neighbors happy.

Are you investing in a commercial shopping center? We can help you get your customers in and out of the building efficiently.  

Are you planning a Zone Change? Traffic Impact Studies help things so much smoother with the planning departments.

Do you need to save the world from the latest cyber-attack? Don't worry about it. We're already on the job.