英语翻译

英语翻译
Schwanen et al.(2001) maintained that metropolitan areas,both in old industrial countries and in developing countries,have evolved from mono-centric structures into poly-centric urban forms.However,they noted that literature on how mono-centric and poly-centric metropolitan structures affect travel behavior is polarized.The work of Schwanen et al.2001 summarized the conclusions obtained from research undertaken in this area.Some authors (e.g.,Gordon and Richardson 1997; Levinson and Kumar 1994) suggest that a de-concentrated structure tends to reduce commuting distance and commuting times.Scholars in this group adhere to the ‘co-location’ hypothesis,which states that firms and households periodically readjust spatially to achieve balanced average commuting distances and duration.Other authors (Cervero 1996; Newman and Kenworthy 1989; Ewing 1997) refute this positive view of the effect of poly-centricity on travel behavior and suggested that decentralization of firms and households has been a disaster for travel behavior.In terms of commuting times,Gordon et al.(1989) have found shorter commuting times for suburban residents than for central-city residents in metropolitan areas with at least three million inhabitants.Because of the stronger congestion effects in high-density mono-centric cities,travel times are higher there than in low-density suburban communities in poly-centric cities.Giuliano and Small (1993) pointed out that a poly-centric pattern of employment centers has a potential for shorter commuting times.Meanwhile,Cervero and Landis (1991) research results suggested that,although overall commuting times and distances may be stable or fall over time,the process of job decentralization may have increased the variation between individual workers.Cervero (1996) maintained that urban development,led by rising affluence,advancing technologies,and other mega-forces,had transformed from a predominant mono-centric form well-suited to point-to-point rail systems to poly-centric forms more conducive to the car and undermining the use of public transport.