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FOR MORE THAN five decadesored cul-de-sacs (Òlollipops팩elopment. Despite their popu-ed by some architects andplanners, particularly New Urbanists, whostrongly advocate the interconnected gridpattern instead (Figure 1). According toproblems of suburbia: an isolated, insularenclave, set in a formless sprawl of similar Reconsidering the Cul-de-Sac are good reasons that the MICHAEL SOUTHWORTH 4 ZELL/LURIE REAL ESTATE CENTER Creative Places (pp. 78-85) ITOLD RYBCZYNSKI To assess the degree to which knowledge-based industries are attracted to regions with ahigh creativity score, this paper examines the location choices of one specific category ofcreative employers: large consulting firms that offer design services in the constructionfield. Research suggests that a high degree of clustering is taking place, since roughly halfof the 50 largest firms in the United States are located in only five urban regions: New YorkCity, Los Angeles, San Francisco, Houston, and Denver. Of the 39 largest design firmsrated in terms of international business, there is a higher degree of clustering: more than70 percent of the firms are located in only eight urban areas, and almost half of these areconcentrated in only two areas, San Francisco and New York. There is likewise a highdegree of clustering among architectural firms: 100 of the 133 largest firms are located inclusters of two or more, and more than half of the largest 100 firms are located in only sixurban regions. The distribution of firms is not related to the size of the urban region. SmallBoston has the same number as large New York; Atlanta and San Francisco have more thanHouston or Philadelphia. The study upholds the hypothesis that the power of place playsrole in attracting creative workers and knowledge-based industries. enough for service and emergency vehiclesto turn around. Because cul-de-sacs offergreater privacy, quiet, and higher propertyvalues, as many houses as possible in thesubdivision are situated on cul-de-sacs andas few as possible are placed on the busierand noisier collector streets. The loop street, a close cousin of thecul-de-sac, similarly discourages through-line it. The loop street has two accessde-sac. Loops and cul-de-sacs are oftenused together in the same development. The cul-de-sac pattern has been strong-ly encouraged by sta

ndards for traffic engi-engineering study on residential street safe-ty, carried out in Los Angeles betweenTransportation Engineers rec-ds also promoted limited access tostreets to discourage through-traffic, curvi-linear design patterns, short streets, elbowturns, T-intersections, and a clear distinc-tion between low-speed access streets and PROS AND CONS Critics object to the cul-de-sac pattern onseveral grounds. It lacks the interconnect-edness of the grid. On leaving a cul-de-sacor a loop street, to go anywhere drivers areobliged to follow a collector street. Routechoices are minimal, so drivers are stuckusing the same path day after day. Also,since so much of the street infrastructure isdevoted to semiprivate dead-end streets, aheavy load of connecting and through-traffic is forced onto a relatively small col-lector and arterial system, contributing tocongestion during peak periods of travel. For the pedestrian, walks can be longto nearby destinations. It is easy to losewn with a civic identity. Main streetsand tree-lined corridors that connectlayout. Moreover, it is usually tiresomein its repetitiveness. Grid developmentscan suffer from monotony, too, ofcourse, but they are easier to visualize enclaves, separated socially and physicallyfrom the larger world, and dependentupon the automobile for its survival.However, despite these criticisms, there areseveral compelling reasons for the successof the cul-de-sac street as a pattern for THE CUL-DE-SAC Cul-de-sac, which means Òbottom of thesackÓ in French, commonly refers to adead-end street. The Oxford EnglishDictionary defines it as Òa street, lane, orplace having no outlet except by theentrance.Ó Since its early use in 1928 aspart of the hierarchical circulation systemRadburn, New Jersey, the cul-de-sac hasbeen the preferred means for controllingprototype for other subdivisions. GeddesSmith, in Clarence Stein픀s 1929 book, Toward New Towns for America Radburn as: ÒA town built to live inÑtoday and tomorrow. A town Ôfor themotor age.Õ A town turned outside-inÑwithout any back doors. A town whereroads and parks fit together like the fingersof your right and left hands. A town inwhich children need never dodge motor-trucks on their way to school.Ó de-sacs based on Radburn were short,straight streets serving few houses. Thesedead-end

streets were intended to providepublic realm for the residents whileallowing safe, slow car movement to andfrom the home. Today, with increased autownership, the cul-de-sac has grown widerand much longer, serving more houses. Acircular space (often more than one hun- ZELL/LURIE REAL ESTATE CENTER 1: The traditional grid patternThe cul-de-sac pattern urthermore, hierarchical, discontinuouser burglary rateseled street layouts; criminalswill avoid street patterns where they mightget trapped. For these reasons, cul-de-sacpatterns have sometimes been retrofitted.For example, the troubled Five Oaks dis-trict in Dayton, Ohio, was restructured tocreate several small neighborhoods by con-ting many local streets into cul-de-sacscent. Overall crimecent. At the same time, homesales and values increased.comparative study of street patternsindicated significant homebuyer prefer-ence for cul-de-sacs and loops. NineCalifornia neighborhoods were examinedin terms of safety performance and resi- However, the cul-de-sac pattern hasseveral important advantages. From theperspective of residents, the model offersquiet, safe streets where children can play,little fear of fast-moving traffic. A discon-tinuous short-street system, unlike thegrid, may also promote familiarity andneighborliness. Cul-de-sacs, being discon-nected, can adapt better to topography.Since they carry no through-traffic, theyoften have reduced standards for streetwidths, sidewalks and curbs. Most impor-tant, the cul-de-sac street pattern is sup-ported by the market: homebuyers willpay premium prices for the most isolatedcul-de-sac lots. Cul-de-sacs are popularwith developers not only because they sellwell, but also because infrastructure costssignificantly lower than for the tradi-tional interconnected grid pattern, whichcan require up to 50 percent more roadeet area and theeet plan. According toutilities paid for the construction of theextensive open spaces and parks. Suchpublic amenities have added value; homeprices in Radburn over the years havebeen higher than those of the convention-al surrounding housing tracts, eventhough the Radburn homes and lots aregenerally smaller. low-density suburban development, butcan serve medium-density row houses andlow-rise apartments. Both Radburn andLondon픀s Hampstead Garden Suburb, forexample, have relativel

y high densities byAmerican standards (9.4 and 8 to 12dwelling units per acre, respectively). Evenneighborhoods such as the residentialcourts of Boston픀s Beacon Hill.In ecologically sensitive sites, the cul-de-sac pattern has distinct value. Unlikewith infrastructure, the cul-de-sac patterncan work around areas of high ecologicalor historical value. Lawrence Halprin픀sea Ranch developmenton California픀s North Coast employed adisconnected pattern of ÒreachesÓ andan/bicycle connector (Figure 2). A morerecent plan for Mayo Woodlands inRochester, Minnesota, uses a similar pat-tern to preserve the meadows and wood-lands of the former Mayo estate whileallowing residential development. ZELL/LURIE REAL ESTATE CENTER Figure 2: PlanÑVillage Homes, Davis, California Philadelphia to Boston (Figure 3). Todaysuch spaces have become high-end realestate, prized for their sense of privacy,century ago, Raymond Unwin andBarry Parker consciously emulated suchpatterns in their designs for HampsteadGarden Suburb in London (Figures 4 and5). ÒFor residential purposes, particularlysince the development of the motor-car,the cul-de-sac roads, far from being unde-sirable, are especially to be desired forthose who like quiet for their dwellings,Ówrote Unwin. It was the first time a mas-used the cul-de-sac and open courtthroughout. An act of Parliament wasrequired to allow the use of cul-de-sacs innew development, since prior cul-de-sacs dentsÕ perception of their street픀s livability.The neighborhoods represented three dif-ferent street layoutsÑgrids, loops, and cul-de-sacsÑbut were matched demo-graphically. The findings suggested thatcul-de-sac streets, and especially the lots atthe end, performed better than grid orloop patterns in terms of traffic safety, pri-vacy, and safety for play. Residents alsopreferred the cul-de-sac as a place to live,even if they actually lived on a through- orloop street. People said they felt cul-de-sacstreets were safer and quieter because therewas no through-traffic and what trafficthere was moved slowly. They also indicat-ed that they were more likely to know theirneighbors. One resident픀s comment wastypical: ÒOur pets and kids are safer whenthere is a no-outlet street; you feel kidnap-is more of a senseof neighborhood.Ó Thus, the study gener-ally corroborated earlier tran

sportationalso support-owever, the surveyed residents oftenere confusing and lackedcoherent structure and uniqueness.Social interaction and neighborhood sensewere not necessarily stronger on the cul-de-sacs, despite perceptions to the con-trary. At the neighborhood scale, problemsassociated with cul-de-sacs may stem morefrom land-use patterns than from thestreet pattern itself. The single-use zoningschools, jobs, and recreation and commer-cial centers at a distance from homes.Separation is further exacerbated by thelack of a well-connected pedestrian/bicyclenetwork. Only rarely is there an intercon-cul-de-sacs with adjacent streets, open CREATIVE CUL-DE-SACS The cul-de-sac pattern presents a dilemmafor the developer seeking the more struc-tured and conceptually clear design offeredby the grid. Is it possible to satisfy both setsacy, safety, quiet, andlower construction costs of cul-de-sacs, aswell as the connectedness, identity, andarchitecturally defined andurope, the Middle East,and early American towns reveals a fre-quent use of such patterns. For example,courts, closes, and quadrangles are foundin medieval English, French, and Germantowns. The residential court is also foundin many early American towns, from ZELL/LURIE REAL ESTATE CENTER Figure 3: Residential court, Beacon Hill, Figure 4: View of cul-de-sac, Hampstead Garden Suburb An ideal suburban residential environ-nents (Figure 7). The courts and closes,each a defined space with its own specialare situated within an overall structure oftreed boulevards and public spaces thatcreate a sense of community. Automobilemovement is limited to collector and arte-rial streets, but pedestrians and bicyclistscan take advantage of the easy intercon-nectedness of a classic grid. The pedestriannetwork parallels the vehicular routes, buteach other, as well as with destinations 1 ZELL/LURIE REAL ESTATE CENTER Figure 5: Plans of closes and cul-de-sacs, Hampstead Garden Suburb Figure 6: Cul-de-sac plan, Radburn were associated with unplanned medievalIn Hampstead픀s court and close arrange-ments, two- to three-story blocks of rowhouses or apartments border a central greenspace and are usually accessed by a narrowservice road. This arrangement creates a rel-atively quiet, pedestrian-oriented environ-ment removed from the public street. Thecul-de-sacs achi

eve similar residential neigh-borhood values. Unlike American postwarcul-de-sacs, those in Hampstead are shortand narrow, with no circular turn-around atthe end, and with the street space definedby the houses. Mid-block pedestrian walksto another street or cul-de-sac beyond, cre-ating an attractive path network for pedes-trians. Roads are designed to discourageough-traffic and vary in both layout andcross-section design according to function.There are always sidewalks. Trees andshrubs, as well as architectural details suchas walls, fences, and gates, make each streetHampstead Garden Suburb influencedsubdivision street design in Britain andNorth America. The layout of Radburn isone example (Figure 6). Houses are clus-tered around automobile-accessible cul-de-sacs. The pedestrian path system expandsinto greenways and parks, with paths con-necting each home, as well as the school.Pedestrians can go almost anywhere withminimal interference from the automobile.Although the open spaces of Radburn arerather lavish, the same values could beachieved with much less open space if Figure 7: Neighborhood design with connected cul-de-sacs some intersections (Figure 9). The barri-ers do not interfere with pedestrians andbicyclists, who can continue to use theinterconnected grid. Originally an exper-iment, the Berkeley scheme was stronglyadvocated by residents of some neighbor-hoods, although disliked by othersbecause circulation patterns were morethrough traffic was eliminated.Nevertheless, support was broad enoughto make it a permanent program.Retrofitting an existing suburban cul-de-sac development to provide pedestrianconnectedness is more difficult. New path-ways would have to be designed to inter-would have to be built on private rights-of-way along lot lines (Figures 10 and 11).To acquire such easements would proba-bly be difficult, since residents are unlike-ly to give up a portion of their land andprivacy. Moreover, most suburban devel-opments of this type are single-use subdi-visions so there is very little to connect such as parks, schools, and shops. A ham-merhead, or formal square configuration,eliminates irregularly shaped lots and cre-ates a well-defined relationship betweenbuildings, street, and the open space at theend of the street.Today there is much interest in traf-fic-calming, and many comm

unities aretaking steps to make streets more pedes-trian- and bicycle-friendly. Some tradi-towns and cities built before the 1920sare being retrofitted to achieve some ofthe values of the cul-de-sac. These neigh-structure, walkability, and accessible landtoday in new residential developmentsigure 8). However, they often sufferfrom the noise and hazards that comewith excessive traffic on local residentialstreets. Berkeley, California, is one com-the problem. In some neighborhoods,the grid system has been converted intocul-de-sacs and loops by the introductionof bollards, large concrete planters, and ZELL/LURIE REAL ESTATE CENTER Figure 8: Pedestrian-friendly gridiron Figure 9: Pedestrian-friendly gridironÑBerkeley barriers Figure 10: Pedestrian-connected cul-de-sacs Figure 11: Pedestrian-connected cul-de-sacsÑBlacksburg, Virginia NEW URBANISM is an alternativeoach for residential commu-nities that promotes the building of com-lorida. There are a number of Canadianarkham, Ontarioand The Village in Niagara-on-the-Lake,Ontario. While the NU movement hasacquired credibility among many archi-have been less willing to embrace key ele-ments of the NU approach. Public works Fused Grid Planning new approach for suburbanmaster-planned communities. FANIS GRAMMENOS To create walkable suburbs it is neces-sary to challenge the established streetdesign standards and regulations thathave emphasized vehicular access at thecommunity form. Traffic engineers andpublic officials need to review existingstandards and establish new frameworksthat support the pedestrian and bicyclistbile. However, rather than tossing out thecul-de-sac as an urban pattern, it is worthreconsidering its values and possibilitiesin creative ways. It has a long history ofuse in a variety of geographic and cultur-al contexts, and could provide optionsthat offer safe and quiet streets as well aspedestrian and bicycle access in a newspatial framework that avoids the prob- CCESS, No. 24, Spring 2004. The authors gratefullyacknowledge the assistance of Dipti Garg, Raymond Isaacs,Mike Larkin, Sungjin Park, and Swapneel Patil with the illutrations. Illustration credits: Michael Southworth, 1, 2, 3, 4, 7, 8, 9, 10;Raymond Unwin, 5; Division of Rare Manuscript collections,Cornell University Library, 6; Eran Ben-Joseph, 11. ZELL/LURIE REAL ESTATE CENT