Roman Roads Notes October 2, 2013 You write:

Via – the Latin word for road.

You write: Summum dorsum – the top layer of a Roman road

The field engineer, assisted by a stake man aligned the road with a groma and ran levels with chorobates.gromachorobates The Groma was used as a sighting device for roads, aqueducts and buildings. The weights on the end of each point of the crossbar sights were to make sure that the groma was kept perpendicular to the ground.

You write: Groma – a device used to build roads in a straight line.

A Chorobate was used to ensure a construction was level. This tool was over 10' ft. long. Water poured into the long groove running down the middle of the top of the Chorobate indicated when it was "level".

You write: chorobate– a device used to make sure roads were level

A plow was used to loosen the soil and mark the trench (fossa) margins. Workmen dug trenches for a roadbed with a depth of 6 to 9 feet, carrying away the dirt in baskets. (fossa)

You write: 6 to 9 feet – the depth of a Roman road

The earthen bed was tamped firm. The foundation of lime mortar or sand was laid to form a level base (pavimentum). Next came stones of about 4 to 5 in. in diameter, cemented together with mortar or clay (statument). This layer could be anywhere from 10 inches to 2 feet deep. (pavimentum) (statument)

The next course (rudus) was 9 to 12 inches of concrete filled with shards of pottery or stone. Atop this layer was the nucleus, a concrete made of gravel or sand and lime, poured in layers with each layer compacted with a roller. This layer was one foot at the sides and 18 inc. at the crown of the road. The curvature was to allow good drainage to the finished road.(rudus)

The top course was the summum dorsum, polygonal blocks of stone that were 6 inches or more thick and carefully fitted atop the still moist concrete. When a road bed became overly worn, this top course was removed, the stones turned over and replaced. A road was 9 to 12 feet wide which allowed 2 chariots to pass in each direction. Sometimes the road was edged with a high stone walkway. summum dorsum

You write: 9 – 12 feet – the width of a Roman road

Milemarkers indicated the distance. A cart, fitted with a hodometer was used to measure distances. Later maps detailed routes, miles towns, inns, mountains and rivers. The first roads were quite straight going over hills rather than around them.hodometer

You write: Hodometer – used to measure distances

A segment of the Appian Way - Just past the tomb of Scipios stands this impressive arch, sometimes called the Arch of Drusus. It was built in the 3rd Century A.D. to carry the Aqueduct Aqua in across the Via Appia. Drusus, father of Emperor Claudius, died in 9 B.C. and a no longer existent arch had been built in his honor near this site, ergo the name. Behind the arch one can see the tower of the Appia gate, today called the Porta San Sebastiano. The Appia gate allows travelers to pass through the Aurelian Walls. The road seen here has modern paving blocks over the ancient road.

The ancient paving blocks and substructure of the ancient road serve as a base for a layer of modern pavement. Remains of tombs line the road.

A road in Saepinum, a wool trading city in Campania.

A close-up of Via Jugaria at the foot of Capitoline Hill. This road had led from the Forum Romanum to the Forum Holitarium (vegetable market) and the Tiber river.

A road in Pæstum - Pæstum was founded by Greek colonists in southern Campania (Italy) on the coast of the Tyrrenean Sea.

A road in Pompeii - Notice the raised stones which allow pedestrians to cross without picking up the dirt of the road in their shoes. The spaces between the blocks were spaced appropriately for the wheels of carts.

One-way in Pompeii - This narrow corridor with a crossing block was probably a via unica (one-way street).

Entombed outside the city precincts - Notice the tombs lining this street in Pompeii - a reminder that tombs were not allowed within city walls throughout the empire.

You write: Cat’s eye – white stones in the road which shine when lit by torches.