functions, serving as administrative and commercial links
between the capital city and its distant territories and con-
necting other cities and ports.
To help the Roman republican or imperial government
control conquered lands, provincial governments were estab-
lished to communicate and enforce the Roman laws. Roads
linked the capital city of Rome to the distant provinces,
thereby allowing the central government to communicate
with its bureaucrats abroad. Provincial governors could carry
out the decrees of the Roman government based on messages
delivered along the routes.
Roman roads were a critical component of the infra-
structure that allowed the economy to grow rapidly from the
middle republic to the high empire. Raw materials, manufac-
tured goods, building materials, and commodities could be
imported and exported along these routes, fueling economic
growth. Th e provincial governments in Roman territories
were also responsible for protecting Roman business inter-
ests abroad, which was possible due to the communication
facilitated by the road network.
Roads were built by soldiers, slaves, and local workers
under the direction of engineers. Local materials and condi-
tions determined the depth of a road’s foundations, its width,
and the technique used to build it. Road foundations were not
fl at but featured an agger, a ridge in the center sloping down-
ward toward the edges of the roadway to facilitate drainage.
Th e construction process was begun by clearing the land
of trees and other major obstacles along a straight route. Th en
a trench was dug, the earth at its bottom was packed down,
and a layer of concrete, or pavimentum, was poured. Th e next
stratum was the statumen, a mixture of stones, followed by
the rudus, a mixture of sand or soil with clay or concrete. Du-
rable, fl at paving stones were cut to fi t together to create a
smooth road surface. Sidewalks for pedestrian traffi c fl anked
many roads, and milestones on the roadside reported the dis-
tance from the road’s origin.
For routes over marshy land the approach was diff erent.
Pavements were laid over wooden rather than concrete foun-
dations. Steep inclines and natural obstacles also required the
builders to deviate from standard building practices. Roads
sometimes followed a zigzag course to minimize the human
eff ort in climbing an incline once the roadway was paved.
While tunnels could be cut through mountains and bridges
could be constructed over rivers, valleys, and marshy land,
sometimes it was necessary to avoid these obstacles altogether,
causing the road to curve or change its straight course.
Th e materials and techniques used to construct Roman
bridges developed over time. Some of the fi rst bridges were
made with wood and rope to connect commercial and resi-
dential areas on opposite sides of the Tiber River. Rome’s fi rst
stone bridge, the Pons Aemilius, was constructed from 181 to
179 b.c.e. to connect the city’s cattle market to the opposite
side of the Tiber.
By using the arch, the Romans were able to build stone
and concrete bridges with one or more spans across valleys
and rivers. Local materials determined the method of con-
struction. In one common method, concrete piers were built
on riverbanks or through ravines to serve as the supporting
columns for the arches. A wooden framework was built and
concrete arches poured onto it, linking the piers. Stone veneer
was then used to cover the bridge’s concrete core. A pulley
system, operated by slaves or animals and possibly driven by
a treadmill, was used to lower huge pieces of stone into place.
When concrete was not readily available, stone was used to
build both the piers and the spans. Bridges that had to be
built quickly or were temporary were made out of wood that
was harvested locally. During military campaigns troops car-
ried small boats for making pontoon bridges to allow speedy
transportation across bodies of water.
Th e legacy of Rome’s network of roads and bridges can be
witnessed to this day from Great Britain to the Middle East.
Th e permanence of the materials and expert engineering em-
ployed in their construction makes these wonders as impres-
sive today as they must have been in antiquity.THE AMERICAS
BY PENNY MORRILL
It is helpful to start by defi ning the diff erent types of road-
ways in the Americas. A path or trail normally follows the
most effi cient route between two points. Paths avoid major
geographic obstacles and usually do not follow a straight line.
Paths are the result of the wear of traffi c and are maintained
by tradition.
Roads are constructed by a labor force. Th ey are intention-
ally prepared surfaces of the landscape that attempt to provide
the most direct route, usually between two points. Formal road
systems have a defi nable width and can incorporate bridges,
roadbeds and pavement, curbs, side walls, drainage culverts,Iron hipposandal from Roman Britain (fi rst to second century c.e.),
found in London; hipposandals were a form of temporary shoe that
could be fastened to the horse’s hoof for use on metal roads. (© Th e
Trustees of the British Museum)
roads and bridges: The Americas 891