This paper discusses the importance of environmental aesthetics and scenic beauty of current
roadside vegetation in the highways, and the necessity for the contribution of users (motorists) preferences in
the integration of scenic beauty of roadside vegetation into its management plans. The results of a questionnaire
survey of motorist’s opinion on the landscape aesthetics and quality of some highways in Tehran city are
presented with their analyses. Findings of the research indicate the roadside vegetation as the most important
elements of highway scenic beauty for the majority of users. High-rise building, historic or cultural landmarks,
farmlands, street lighting and advertisement boards found with lower level of importance to the passengers. A
strong positive tendency of respondents found towards variety of vegetation types instead of a uniform
composition. The most preferred combination of plant types of road were preferred were: trees in the
background, grass and flowering herbs in the foreground and shrubs in the middle. In our case study, dissatisfaction
with vegetation type and combination was reported lower among those who travelled once or twice a month
or longer, compare to those who travelled the site more frequently in a daily or weekly basis. This indicates
that for less frequent users the roadside vegetation was reported almost satisfactory, as their personal cognition
of a route is less affected by their prior knowledge. However, the preferences of motorists who used the
highway more frequently, showed a great tendency with planting design patterns of trees in background and
shrubs in the foreground.