This study intended to address the problem of damaged (collapsed, cracked and decreased soil strength) road pavement structure built on clay soil due to clay soil properties such as low shear strength, high soil compressibility, low soil permeability, low soil strength, and high soil plasticity. Previous research reported that ground granulated blast slag (GGBS) and fly ash can be used for clay soil stabilizations, but the results of past research indicate that the road pavement construction standards remained unfulfilled, especially in terms of clay’s subgrade soil. Due to this reason, this study is carried out to further investigate soil stabilization using GGBS and fly ash-based geopolymer processes. This study investigates the effects of GGBS and ratios of fly ash (solid) to alkaline activator (liquid) of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, cured for 1 and 7 days. The molarity of sodium hydroxide (NaOH) and the ratio of sodium silicate (Na₂SiO₃) to sodium hydroxide (NaOH) was fixed at 10 molar and 2.0 weight ratio. The mechanical properties of the soil stabilization based geopolymer process were tested using an unconfined compression test, while the characterization of soil stabilization was investigated using the plastic limit test, liquid limit test, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the highest strength obtained was 3.15 MPA with a GGBS to alkaline activator ratio of 1.5 and Na₂SiO₃ to NaOH ratio of 2.0 at 7 days curing time. These findings are useful in enhancing knowledge in the field of soil stabilization-based geopolymer, especially for applications in pavement construction. In addition, it can be used as a reference for academicians, civil engineers, and geotechnical engineers.

Functional and structural failures in the pavement structure can be distinguished. The Road state Value measures the functional state of road pavements in managing flexible and stiff pavements for urban roadways in Indonesia. The pavement condition assessment is based on the unevenness of the pavement surface, rutting, and direct surface damage. This research aims to assess the worth of road damage on flexible and rigid pavements and establish a special relationship between Present Serviceability, International Roughness, and Pavement Condition Index. Direct observation in the field is utilized to obtain data on the different types of damage. According to the field survey data, the most common types of damage for flexible pavements were filled (56), followed by longitudinal cracks (18) for rigid pavements. PSI, IRI, and PCI models have a strong association, with the R2 value found to be acceptable. It shows a high correlation with scores above 90% for good, medium, and inferior roads. The resulting equations establish a strong link between IRI and PCI. Furthermore, the validation findings demonstrate that the model is entirely accurate.

Letjen S. Parman road is one of the urban roads with a length of 4.2 km located in West Jakarta area and is a primary arterial road with three two-way lanes divided, where the median is a toll road in the city of Jakarta. This study aims to evaluate road pavement conditions functionally and compare the value of road pavement conditions based on two methods, namely Pavement Condition Index (PCI) and Surface Distress Index (SDI) which are used as the basis for knowing the type of road maintenance handling. This study uses direct observation method in the field by conducting a visual survey of the condition of pavement, where the length of this road is divided into 42 segments with one segment is 100 meters. From the results of the road damage research Letjen. S. Parman using pavement condition index (PCI) and Surface Distress Index (SDI) method there are no significant differences in results. For pavement condition index (PCI) method get a percentage result of 90% with perfect value and 10% with excellent value while with Surface Distress Index (SDI) method get a percentage result of 96.5% with good category and 3.5% with medium category.

Intersection Telkom Jatiasih is one of the congestion point in Bekasi City. This is at leave because of the high volume of traffic and also a busy route from Bekasi to Jakarta and the surrounding area, plus the direction to the toll gate Jatiasih. There is no sign – traffic sign making of Intersection Telkom Jatiasih is an unsignable junction, this is what causes the flow of irregular vehicles causing congestion. The data retrieval method is done by surveying directly to the research site. Based on survey result in Telkom Jatiasih intersection, the highest vehicle volume accurred in the afternoon of Monday, April 29 th, 2019. Calculated results based on the field survey result data using the MKJI 1997 book guidelines, obtaining the Degree of Saturation (DS) = 1,86 with the Level Of Service F value, indicating the stopping of the vehicle current at the congestion point such as the meeting path, or repair lanes that cause a long queue of vehicles. On the road Of Wibawa Mukti II Highway – Jatiasihi the vehicle flows are still recorded stably with the Degree of Saturation (DS) = 1,16 with a Level Of Service F value which means the level of road service is still stable. From the research results get an alternative solution Telkom Jatiasih intersection is in alternative 2 because it gets a decrease in the Degree of Saturation (DS) = 1,11 with the value of the Level Of Service F which means high traffic flow condition, but Current conditions are still stable.

A common phenomenon in developing countries is that the function of the pavement in the road network will experience structural damage before the completion of life is reached, and the uncertainty of pavement damage is difficult to predict. Planning for maintenance treatment depends on the accuracy of predicting future pavement performance and observing current conditions. This study aims to apply the Markovian probability operational research process to develop a decision support system predicting future pavement conditions. Furthermore, it determines policies and effectiveness in managing and maintaining roads. A standard approach that can be used by observing the history of pavement damage from year to year is to estimate the transition probability as a Markovian-based performance prediction model. The results show that the application of the model is quite optimal, changes in pavement conditions after repair can be easily compared with an increase in good condition, reaching 92.8%. Routinely and consistently handling road deterioration will give favorable results regarding pavement condition value. This will ease in the management of the road network and the accomplishment of the optimal maintenance and repair policies. Doi: 10.28991/CEJ-2024-010-09-012 Full Text: PDF

Malaysia is listed as one of Asia's developing countries with high-road accidents rate. The accident involves the most between the motorcyclist and other vehicles such as a passenger car which is 17 times safer than the motorcyclist. Current research reveals that the three major forms of incidents in Malaysia are single-motorcycle incidents, passenger car crashes and cars–motorcycles crash. In general, the lack of accuracy of road geometric design, traffic volumes and overlapping movements of vehicles was the main cause of road accidents in Malaysia, which caused drivers to make mistakes and errors due to road geometric characteristics and traffic environments. However, during our recent COVID-19 pandemic, the traffic volumes are relatively low in the whole country as the government announces the movement control order in March 2020. The country was almost completely lockdown (people and vehicles' movements were controlled). In contrast with the reduction of the traffic volumes, the number of crashes shows relatively high numbers. This phenomenon can be derived so that other factors cause vehicle crashes and fatalities should be considered. Several factors related to road geometric such as lane width, shoulder width, access point, curve length and tangent length are considered in developing profiles of operating speed for motorcycles and cars formed of tangents and curves. The analysis of the geometric factors and traffic environments took place at federal road F0050 from 21 to 25 km in Johor, Malaysia. This study was carried out using GPS (DG-200) where the data (vehicles tracked movements) on the continuous speed profiles used a current method of analysis to determine the profiles of road design consistency for motorcycles and cars. The profiles are used to measure the importance index of the integrated design consistency model of the road. The model depends on parameters such as the confine region of speed profiles, average speed, and velocity deviation standard of the profiles. Therefore, a special software of ACAD was used to build the profile of the consistency model. The design accuracy of the speed profile in traffic and safety assessments are affected by the integrated-consistency model. The highest number of accidents has been identified at 24 km at F0050 based on the area design consistency where poor design is the integrated quality consistency model for car and motorcycle. The study shows that crashes and fatalities are not fully affected by traffic volumes but road design performances and driving behaviors.