Comparative investigation of the quality of urban streets of Tehran based on the criteria of excellent streets Case study: Enghelab, Keshavarz and Fatemi streets

1-      Introduction
The increasing growth of urbanization in recent decade and occurring most of the economic and social activities of human being in urban environments cause that the city is considered as a place a citizen spends much time and it is one of the effective and important places in which the majority of memories, experiences, emotions are formed. Thus, cities play important role in cultural construction and formation of individual and social personality of human being. Public spaces of city as composed of two elements of street and square are considered as the most important part of cities in which most routine activities of people are occurred and they play the important role in formation of social personality of human being. As urban streets cover 75% of cities are raised as the cultural symbol and defining the economic, social and cultural structure of city. Sometimes, they are the civil life position of city and occurrence of social activities of citizens in urban life and they are of great importance. Thus, organized design and their development make the social and cultural life quality of people more enriched. Today, the role of urban streets is weakened as a place for social interactions, visits, contacts and the gathering place of citizens due to the development of motorized vehicles. This caused that streets are turned into vehicle-based streets and they play communicative space role. To evaluate the quality of urban streets, based on the effective factors from the view of urban planners and considerable studies in this regard and the views of experts, Delphi method is applied to collect their views, 4 indices and 16 components as the criterion of selection of components, their share components from the view of theorists are considered in this study. These indices and components are shown in Table 1.
 
 
Table 1- Effective indices and components to create excellent street





Indices


Aesthetic principles


Social and cultural


Environmental


Service and welfare




 
Components


Lighting


People-based


Vegetation


Furniture




Vitality


Safety and security


Climatic comfort


Availability




Perception


Identity and belonging


Environment-friendly materials


Hygiene




Alignment


Iranian-Islamic symbols


Appropriate disposal of runoff


Comfort





 
2-      Study area
Enghelab, the distance between England square to Valiasr intersection, Fatemi streets, the distance between Fatemi square to Fatemi intersection and Kargar Shomali and Keshavarz, the distance between Valiasr square to Keshavarz intersection and Kargar Shomali are located in one of the most crowded townships of Tehran city on one hand and the importance of designing and improvement in these regions on the other hand and as designing and improvement of urban street consistent with the designing principles can meet the economic demands by increasing competitive capability of city from economic aspects and absorbing the investors. Also, it is a key factor to improve the emotions and morale of the residents (increasing life quality )  and it is an exact criterion for pathology of urban development and it has necessary requirements as the case sample to be investigated.
3-      Study method
The method of the study is descriptive-analytic and field design. At first, the theoretical framework of this study is based on data collection of library resources, article and internet references. To identify the studied site, field study is performed by aerial images and maps. To complete the required information, recognizing the existing condition (environmental, structural and perspective) is done via observation and questionnaire. This study applied AHP method to determine the weight of indices and effective componets to achieve excellent street in urban space by Delphi method. Then,11 Expert choice was used for data analysis. For data collection, the pairwise comparison of the indices and components is done by 34 faculty members and experts specialized in urban planning, environment design, green space design and environment engineering. Their valuation is based on their experiences and studies. Later, these indices and components are evaluated by citizens including pedestrians and shop owners in three streets of Enghelab, Fatemi and Keshavarz.
To evaluate the effective factors on creating excellent streets, a questionnaire is applied. In each of 3 streets, 100 questionnaires and totally 300 questionnaires are distributed randomly among the citizens in spring consisting 5% of the population of users and employees to compare these three stress with the criteria of urban excellent streets.
It can be said the scores are given to 30 questions designed by Likert design from the citizens. The items are consisting very low, low, average, good and very good to evaluate the questions. Then, to compute and summarize the scores, the following formula is used.
 
N=
N = The sum of score of each index
  = The mean of scores of 100 questionnaires  
  =      Component weight
   =       Index weight
   = Number of components
Finally, the sum of the mean of scores is added and again averaging is performed to perform the prioritization of each of the streets based on score mean.
4-      Study findings
After the investigation of the indices and components by 34 experts, field study is performed of the case samples. Later, the results of the survey and information are analyzed. Of the sum of the views of 100 respondents in each street, Keshavaraz street by the mean score 0.207 had good quality compared to Fatemi street with score mean 0.165 and Enghelab street with score mean 0.154.  The analysis of social and cultural component of streets showed that Keshavarz street with mean score 0.282 compared to Fatemi and Enghelab streets with the score mean 0.219 and 0.196, respectively had relative superiority and based on the results, the service and welfare component of Keshavarz street with the score mean 0.278 showed high value compared to Enghelab street with score mean 0.228 and Fatemi street with the mean score 0.219. Here, environmental component of Keshavarz street with mean score 0.163 compared to Fatemi and Enghleab streets with the score mean 0.150 and 0.116 had relative superiority and finally aesthetic component showed that Keshavarz street with score mean 0.084 compared to Enghelab street with score mean 0.077 and Fatemi street with score mean 0.075 had better condition.
5-      Discussion and Conclusion
Generally, in this study, at first the effective factors on quality of urban streets are investigated, then, they are evaluated in three streets of Keshavarz, Fatemi and Enghelab. The results of these evaluations in three streets of Keshavarz, Fatemi and Enghelab showed that Keshavarz street with the mean score 0.207 compared to Fatemi streets with the score mean 0.165 and Enghelab with score mean 0.154 had good quality. Finally, social and cultural indices in four components in these three streets were not in good quality and by improving the quality of these componets, they are considered as the most important components to create excellent urban streets. Regarding the welfare services index, Enghelab and Fatemi streets had problems in three componets of hygiene, furniture and comfort and by improving their quality, we can be hopeful regarding the total improvement of quality of these three streets. Regarding environmental index, Enghelab and Fatemi streets had not good quality in four components and by improving their quality, we can increase the quality of these two streets. On the other hand, Keshavarz street has good quality in terms of vegetation and climatic comfort and by improving the appropriate disposal of runoff and using environment-friendly materials in this street, we can increase its quality. Regarding aesthetics, all components had low quality in three streets and to increase the quality of these streets, we should improve them