In Baghdad city, Iraq, the traffic volumes have rapidly grown during the last 15 years. Road networks need to reevaluate and decide if they are operating properly or not regarding the increase in the number of vehicles. Al-Jadriyah intersection (a four-leg signalized intersection) and Kamal Junblat Square (a multi-lane roundabout), which are two important intersections in Baghdad city with high traffic volumes, were selected to be reevaluated by the SIDRA package in this research. Traffic volume and vehicle movement data were abstracted from videotapes by the Smart Traffic Analyzer (STA) Software. The performance measures include delay and LOS. The analysis results by SIDRA Intersection 8.0.1 show that the performance of the roundabout is better than the signalized intersection but experiences high delay, and low LOS. Therefore, alternatives are proposed to improve the performance for current and future traffic volumes with low-medium delays.

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Sustainable development is represented the great challenge of meeting the requirements of humans for the industrial products, transportation and influence of waste materials whereas sustaining and protecting environmental quality. The main purpose of the current research is to assess the physical properties of base and modified asphalt binders with selected percentages of nano and micro size of steel slag material. Significant physical characteristics of the modified asphalt including; ductility value, softening point, penetration index, penetration grade and viscosity values were measured. Three percentages of nano and micro size of iron slag as (1, 2, and 3) % by of the asphalt weight were blended by a shear mixer set at (3,000) rpm and mixing period fixed at 20 min at 145 °C. In general, the results have shown adding nano and micro steel slag powder that increased the viscosity values, softening point temperature, whereas reduced the ductility and penetration values. Concerning penetration index values for the modified asphalts are improved by adding slag percentages. However, the modified asphalt binder with 3% of nano slag showed a higher value of penetration index (PI) thus, it has an encouraging influence on the resistance of rutting failure.

Warm mix asphalt (WMA) is mixed at temperatures ranging 20-50 °C lower than those in which called hot mix asphalt (HMA). The use of synthetic zeolites as a warm mix asphalt additive has exhibited many additional advantages, such as a reduced susceptibility to permanent deformation. However, there are also indications that the use of synthetic zeolites as a warm mix asphalt additive for some percentages increases the moisture sensitivity of pavements except for 5% there is a slightly improve. The results of the study indicated that the selected percentages of synthetic zeolite to the warm asphalt differently effected on the mixture properties. When the mixture properties were compared, it was observed that WMA with 3% of synthetic zeolite reduced the indirect tensile strength value, also the WMA mixture with 5 % of synthetic zeolite decreased the rut depth of the mixtures and slightly increased in the tensile strength ratio (TSR).

Urban mobility problem in Nigeria is on the increase, due to rapid growth in traffic that is not matched with the existing transport infrastructure, resulting in traffic congestion. Headway, a measure of level of service of a roadway, could be instructive in addressing this problem, hence this study. Headway, traffic flow and travel speed were collected for morning and evening peak periods for three consecutive weeks for two selected sections of a road in Ile-Ife, Osun state, using normal procedure. The obtained headway data were subjected to statistical analysis. Headway models were developed using regression analysis and the developed models were evaluated using Adjusted Coefficient of determination (R2). The results showed that the traffic along the road was heterogeneous. The maximum safe speed (85th percentile speed) was 31.20 km/hr, while the minimum allowable speed (15th percentile speed) was 28.50 km/hr. The ratio of flow to capacity (v/c) of the road was 0.65 and thus characterised to operate at level of service C. The headway models were h =0.001n2 -0.418n2 + 35.401, h = 0.002n2 – 0.569n + 42.122 , R-square values of 0.942 and 0.928 and minimum headway values of 5.35 sec. and 5.52 sec. For sections one and two respectively. The road is therefore prone to congestion.