Roundabouts are progressively being utilized on occupied arterial streets for traffic quieting purposes. Be that as it may, on the off chance that one indirect leg is close to a conveyance center point, for instance, stopping territories of strip malls, the passage traffic volumes will be especially high in pinnacle hours. On the basis of the Al-Turkman Roundabout, which is one of the most important roundabouts in Baghdad city, linking the areas of east of Baghdad to the city center in the area of Bab Al-Moatham. This area is characterized by its high traffic volumes (congestion), especially at peak periods causing a low level of service (LOS) with increased travel time delay, costs, and CO2 emissions. The research relied on the use of the SIDRA software to assess these variables by collecting traffic volumes in this area. The research proposed a series of planning procedures which are divided according to serial time scales. These planning procedures are to address the problem of congestion and traffic jams in the area, improve the level of service, and reduce travel time, cost and CO2 emissions. The research concluded that the application of the planning proposals in the study area has improved the level of service from E and F to C, reduced travel time by 16%, reduced costs by 25% and reduced CO2 emissions by 29%.

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The aim of this paper is to review research conducting the impact of land use variables on the travel behaviour. It is focused on the density as an important measure of land use that reflects the interaction with the transportation system. The effect of density has been addressed years ago; therefore, papers have been published since 1960s were reviewed in this paper. These papers are classified into two groups according to the most common measure of the density and the most common variables of the travel behaviour considered in these researches. The first group contains about 26 papers published before 2000 while the second group contains about 45 papers published after 2000. It has been noticed that the population density is the main term of density used in the first group while the employment density and the configuration of densities are integrated as measures in the papers published after 2000. The direct relationship with mode choice and travel length has been approved. However, there are some gaps are identified in the discussion and conclusion sections, such as the effect on the trip production rate, the type of trips according to its purposes, internal and external, and weekdays and weekend.

Traffic accidents are the most critical problems related to safety and security in the city, and they have negative effects on human life and psychological, health, and economic impacts on people, society, and the city. After 2003, the number of cars increased in Iraqi cities and traffic accidents increased, as the number of traffic accidents in Iraqi cities reached between 8-11 thousand accidents annually during the period 2012-2018. The percentage of accidents in Baghdad Governorate 12.1 % of all incidents in Iraq, 66% of accidents in Baghdad Governorate are inside the Baghdad city (the capital), divided by 70 % in Rusafa and 30% in Karkh in 2017 and 2018. By preparing a questionnaire on the causes of accidents in Iraqi cities, it showed that the most important reasons are the lack of adherence to traffic laws and the weak knowledge of them and old laws and their non-conformity with technological developments and communications in the transport sector. The research proposes to develop an integrated framework that adopts sustainable transport along its social, institutional, and economic aspects to solve the problem of accidents in Baghdad city.

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