Read an Excerpt
Streets and the Shaping of Towns and Cities
By Michael Southworth, Eran Ben-Joseph
ISLAND PRESSCopyright © 2003 Michael Southworth and Eran Ben-Joseph
All rights reserved.
Gritty Cities and Picturesque Villages
The Origins of Suburban Street Design Standards in England and the United States
The joy and pain of urban existence, the comfort or hardship of it, its efficiency or failure are influenced by the wisdom or the thoughtlessness with which streets are platted.
—Charles Mulford Robinson, 1911
A BRIEF LOOK AT STREET DESIGN STANDARDS OF ANTIQUITY
Today's standards for street design have roots in ancient practice and road building technologies. Roman street standards and paving ordinances provided the foundation for modern road building technique and design. In Mediterranean towns streets were typically narrow and wheeled traffic was controlled, thus eliminating the need for wider streets. Moreover, the hot climate made the shady narrow streets more comfortable. In the first century B.C., the Roman architect and engineer Vitruvius advised that streets should be laid out to control winds, which would bring humidity and disease into the city: "When the walls are set round the city, there follow the divisions of the sites within the walls, and the layings out of the broad streets and the alleys with a view to aspect. These will be rightly laid out if the winds are carefully shut out from the alleys. For if the winds are cold they are unpleasant; if hot, they infect; if moist, they are injurious.... For when the quarters of the city are planned to meet the winds full, the rush of air and the frequent breezes from the open space of the sky will move with mightier power, confined as they are in the jaws of the alleys. Wherefore the directions of the streets are to avoid the quarters of the winds, so that when the winds come up against the corners of the blocks of buildings they may be broken, driven back and dissipated." Vitruvius went on at length on the names and characteristics of the different winds and how to lay out the streets accordingly.
The earliest known written law regarding streets dates back to about 100 B.C., and fixed the width of Roman streets at a minimum of 15 feet (4.5 m). Previous street construction did not follow any regulations. In Pompeii until 200 B.C., the streets were paved at various widths while the houses facing them were low and small. When the peristyle or courtyard house came into fashion from 200 B.C. to 100 B.C., houses encroached into the street and formed narrower arcade streets similar to those of Hellenistic cities. Romans later adopted this style, which reached its peak in the Imperial period. The tendency to build higher houses created dark and narrow passages, insufficient for wheeled traffic. As a result, in 15 B.C. Augustus limited the height of buildings to 66 feet (20 m) and no more than six stories. He also made a new law fixing the main intersecting axes of the grid: the decumanus, the east–west processional road, was to be 40 feet (12.2 m); the cardo, the main north–south road, was set at 20 feet (6 m); and the vicinae, side roads, were to be 15 feet (4.5 m).
Streets of Rome were usually paved with basalt slabs. Elevated sidewalks paved with peperino stone were usually built on both sides of the street and took as much as half of the total street width. Roads outside the city were either paved or, at minimum, graveled. In 47 B.C. traffic congestion became such a problem citywide that Caesar forbade transport during the daytime except for materials for public buildings or for festivals and games. Wagon transport, including the removal of refuse and rubble to the dumps outside the towns, was restricted to nighttime.
While the Roman city street, with its elevated sidewalks, became the prototype for modern street design, it was viae militares, military roads, that were the foundation for contemporary construction techniques. By the peak of the Roman Empire in 300 A.D., almost 53,000 miles of military roads had been built connecting Rome with the frontiers. The typical Roman road was constructed of four layers: flat stones, crushed stones, gravel, and coarse sand mixed with lime. Paving stones and a wearing surface of mortar and a flintlike lava were laid on top. Roads were usually about 35 feet (10.6 m) wide, with two central lanes 15.5 (4.7 m) feet wide for two directions of traffic, and were lined by freestanding curbstones 2 feet (0.6 m) wide and 18 inches (45 cm) tall. On the outer side of the curbs a one-way lane about 7.5 feet (2.3 m) wide was laid. This basic section and construction technique set the standard for road construction in Europe until the late eighteenth century.
After the collapse of the Roman Empire in 476 A.D., many Roman cities fell into a prolonged period of decline and decay. With the breakdown of administrative and political systems, controls over land eroded. Formerly public spaces such as streets were encroached upon. This erosion of the clear and regular Roman grid is seen in the evolution of the street patterns of Bologna, Verona, Naples, and many other cities built by the Romans. The superb paved Roman roadways deteriorated into an impassable ill-drained dirt road system, halting long distance vehicle travel. Carts and wagons were confined to farm and local use, while land travel was restricted to pedestrians or horses. Surviving cities struggled with repair and rebuilding of their defenses. Most cities were contained by enclosing walls and a few major streets led from the gateways to a focal center. Local internal streets were merely narrow passageways defined by the building walls and overhead arches. Streets were flagged with stones and often incorporated steps to facilitate pedestrian movement.
With the steady growth of towns and cities during the ninth and tenth centuries, overcrowding and congestion became a serious problem. Confined by existing defensive walls, buildings grew higher, and without public controls over construction and land use, individuals encroached on the street space. The lack of sanitary conveniences and regulations, along with deteriorating pavement, added to the hazardous and unhealthy conditions. Streets were filthy. As late as 1372, Parisians were permitted to throw waste from their windows whenever they chose after giving a warning by shouting three times.
By the eleventh century Europe entered an era of expanding population, travel, and trade. Although land routes remained largely neglected, sea navigation and exploration saw impressive advancement with the opening of trade to the Far East. As the power of the merchant class grew, they exerted pressure on the civic authorities to improve the street network.
With the revival of interest in the documents and monuments of antiquity during the thirteenth century, European architects such as Alberti, Palladio, Cataneo, and Scamozzi once again stressed the importance of well laid-out streets and approaches. Leon Battista Alberti (1404–1472), a major force in this revival, sought to advance the social and civic conditions of his time by studying ancient Classical architecture. For him, good architecture and city planning worked together, and encompassed skillful siting, regard for health conditions, adequate water supply, efficient construction techniques, thoughtful street layouts, and harmony of design. Alberti suggested two approaches to street planning according to the character of the city. In De re aedificatoria, his classic work on the laws of building, he wrote: "When they come to the Town, if the City is noble and powerful, the Streets should be strait and broad, which carries an Air of Greatness and Majesty; but if it is only a small Town or a Fortification, it will be better, and as safe, not for the Streets to run straight to the Gates; but to have them wind about sometimes to the Right, sometimes to the Left, near the Wall, and especially under the Towers upon the Wall; and within the Heart of Town, it will be handsomer not to have them strait, but winding about several Ways, backwards and forwards, like the Coarse of a River."
Alberti stressed the practical application of winding streets as a means of protection and defense against an invading enemy. Yet he also acknowledged their aesthetic potential. "Moreover," he wrote, "this winding of the Streets will make the Passenger at every Step discover a new Structure, and the Front and the Door of every House will directly face the Middle of the Street; and whereas in larger Towns even too much Breadth is unhandsome and unhealthy, in a small one it will be both healthy and pleasant, to have such an open View from every House by Means of the Turn of the Street." He goes on to address the design of private streets: "The private ones should be like the publick; unless there be this Difference, that they be built exactly in strait Lines, which will answer better to the Corners of the Building, and the Divisions and Parts of the Houses. The Ancients in all Towns were for having some intricate Ways and turn-again Streets, without any Passage through them, that if an Enemy comes into them, he may be at a Loss, and be in Confusion and Suspence; or if he pushes on daringly, may be easily destroyed."
The simple geometry of the straight street appealed to Renaissance architects for its pure form, as well as its potential for opening up dramatic perspectives to civic or religious landmarks. Military strategists also argued that the straight street would facilitate control in times of civil unrest or invasion. Thus, straight streets were inserted into the medieval urban maze. At the request of the Doge, architect Galeazzo Alessi (1512–1572) designed an early example of the straight street, Strada Nuova, in Genoa in 1550. This monumental street, which survives today as Via Garibaldi, was lined with the grand palaces of the new merchant class. The design specified uniform size and alignments of the palaces along the 25-foot-wide paved street, with entrances placed symmetrically opposite. New bourgeois suburbs designed in the form of rectilinear gridirons were attached to the old cities. Turin added three grid extensions to its Roman core, and later, Berlin and Vienna, along with many other cities, also added grid suburbs.
Andreas Palladio (1518–1580), another Italian architect inspired by Roman planning and architecture, envisioned an ideal city street. It was to be paved and would divide "the place where men are to walk, from that which serves for the use of carts and of cattle." In order to protect pedestrians from heat and rain, Palladio recommended the construction of porticos on both sides of the street: "I should like that the streets were divided, that on one and on the other part there were porticos made, through which the citizens might, under cover, go and do their business, without being molested by the sun, by the rains and snow." To ensure drainage the street was concave in the middle and the sidewalks slanted toward the street.
Outside the city gates, Palladio recommended that streets have a minimum width of 8 feet (2.4 m) and be lined with trees on either side. Unlike the inner city streets, the center had a crowned, paved surface for the sole use of pedestrians. The two sides were made of sand and gravel for use by carriages and cattle. A stone curb separated the two areas and incorporated large milestones.
The French also contributed to the standardization of streets. In 1716, Louis XIV formed a body of road and bridge experts and engineers—the Corps des Ponts et Chaussées—to supervise public work. This was the first body of civil engineers in Europe maintained by a government. An associated school, the first professional civil engineering school in Europe, was established in 1738. In 1775, Pierre-Marie-Jerome Tresaguet, the head engineer for the board, developed a new type of relatively light road surface to replace the massive Roman cross section that was still in use. It was designed on the principle that the subsoil should support the load. Before this time roads were designed in the Roman manner to support heavy loads through thick pavements. Tresaguet's road section was constructed with compacted broken fine stone on top of a square stone base. The roadway crown rose 6 inches (15 cm) and had a consistent cross section of 18 feet (5.5 m).
In England, London's Westminister street improvement program created the first known "modern" city street section in 1765. Streets were lowered and leveled, and footpaths on each side were elevated, paved, and defined by curbstones. The carriageway was paved with smooth granite sloping to small drainage channels on both sides of the curbs. In 1816, John Loudon McAdam, the general surveyor of Bristol, started a road building program utilizing his design for a new surface. His method used well-drained, compacted subgrade soil to support the load while the top layer acted only as a wearing surface to shed water. The 18-foot (5.5-m) crowned carriageway had only 10 inches (25 cm) of surfacing material, consisting of broken stones in small angular fragments not more than 2 inches (5 cm) in diameter laid in loose layers that were compacted under traffic. His solution was widely accepted, and by 1820 more than 125,000 miles (200,000 km) of roads were surfaced in England using this method. Modern-day macadam, derived from this approach, is now used worldwide.
Early road and street building in North America was limited to colonial settlements and trading trails. By the seventeenth century road and street building paralleled that of England. Archeological excavations point to Pemaquid in Bristol Township, Maine, founded in 1625, as the first known site of a paved American city street. Built according to European prototypes, the street was paved with large stones. Archeologist John Henry Cartland describes it as "a short section of street about ten feet above high water mark, leading down a fine easy sloping field toward a small beach.... The larger stones form what we term the main street, which is thirty-three feet in width including the gutters, or water courses.... No prettier place could have been found along the shore, and it was in close proximity to the fort."
The first engineered road in the United States was a private toll turnpike from Philadelphia to Lancaster, Pennsylvania, constructed in 1795. Its 62-mile (100-km) length was 20 feet (6 m) wide and was covered with broken stone and gravel. It lacked curbs but had cleared unpaved shoulders on both sides. A major act of road improvement in the United States was initiated in 1816 with the creation of the first American State Board of Public Works in Virginia, headed by Colonel Loammi Baldwin, the pioneering engineer known as the "father of civil engineering in America." The act provided for a corporate body with the power and funding to undertake public projects supervised by a principal engineer or surveyor. Soon after, a similar action was passed in South Carolina in 1817 and in Kentucky in 1835. The main result of these actions was improvements in resurfacing using the McAdam technique, which was first used in Maryland in 1823. With major railroad building worldwide, road building was virtually brought to a halt over the next 60 years, 1840–1900, and was confined to essential urban resurfacing improvements.
THE FIRST SUBURBS IN ENGLAND
During the industrial period in Britain, urban road design and improvement often were responses to crowding and degradation of the urban environment. The Report on Conditions of the Laboring Classes in the Town of Leeds (1845) states: "Let the poor family, consisting of a man, his wife, and five children, two or three of whom are adolescent, be imagined occupying one of these chambers, in a cul-de-sac, or in an undrained and unpaved street, seven human beings, each requiring 600 cubic feet of breathing room, shut up in a chamber not containing more than 1000 feet for the whole ... both parents and children rising in winter and summer at five o'clock in the morning and laboring in other unhealthy atmospheres ... and returning to the limited atmosphere of the night, unchanged, because unable to be improved, owing to the defective sanitary regulation, or an entire absence of them;—and the mind that so thinks, draws a picture which the theater of any large manufacturing town pourtray (sic) in thousands of instances." The exploitation of street space arose in the absence of any regulations or restraints to manage the environmental impacts from the growing population. In 1842, only 86 of the nearly 600 streets of Leeds were under municipal control and were sewered and paved. In 1844, the First Report of the Commissioners of the State of Large Towns and Population Districts, published in London, advocated a fundamental rethinking of street design. Regulating street width and direction was seen as a key to controlling growth and ensuring long-term planning. The commission set up a hundred-year program: "The widening and straightening of streets should be done in concert, rather than leaving improvement to an occasional widening project. The determining feature in each street would be an imaginary center line drawn on an official map from which all building lines could be controlled in the future. As the old houses became ruinous they would be pulled down and new structures erected farther back."
Excerpted from Streets and the Shaping of Towns and Cities by Michael Southworth, Eran Ben-Joseph. Copyright © 2003 Michael Southworth and Eran Ben-Joseph. Excerpted by permission of ISLAND PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.