A traffic prediction model that incorporates relevant demographic variables for county roads was developed. Field traffic data were collected from 40 out of 92 counties in Indiana. The selection of a county was based on population, state highway mileage, per capita income, and the presence of interstate highways. Three to four automatic traffic counters were installed in each selected county. Most counters installed on the selected road sections were based on the standard 48-hour traffic counts. Then, the obtained average daily traffic was converted to annual average daily traffic by means of adjustment factors. Multiple regression analysis was conducted to develop the model. There were quantitative and qualitative predictor variables used in the model development. To validate the developed model, additional field traffic data were collected from eight randomly selected counties. The accuracy measures of the validation showed the high accuracy of the model. The statistical analyses also found that the independent variables employed in the model were statistically significant. The number of independent variables included in the model was kept to a minimum.

A mixed logit approach was used to investigate the relationship between routine maintenance and pavement performance. A discrete model was developed to examine how pavement performance levels affect the probability of performing maintenance on pavement sections. Another continuous model was formulated to investigate the effect of maintenance on the level of pavement performance. Maintenance was considered a discrete event representing a binary choice of its being performed on a pavement section or not. Pavement performance levels were represented by roughness numbers. Other variables included were pavement thickness, pavement loading, and a regional factor. Pavement thickness was assumed to represent initial construction, and traffic loadings were in the form of equivalent single-axle loads. The regional factor represented the weather and climatic differences between the northern and southern regions. A two-stage procedure was applied to evaluate the mixed logit approach. The data from the Interstate highways in Indiana for 1984 to 1985 were used for model estimation. The mixed logit approach produced much better results than the single-equation method in specifying the models in terms of coefficient signs and their significances. The results confirmed that pavement roughness was affected by maintenance and that the decision to undertake maintenance was influenced by the expected level of pavement roughness.

Climate change is a result of the environmental degradation due to human activities and has the potential to become a climate disaster that threatens human life and causes social problems. Through the ESF, World Bank expect that infrastructure development can go hand in hand with environmental and social safeguards. To obtain information about the level of satisfaction of the performance of this ESF indicator, this study was conducted using the Importance Performance Analysis method to compare the expectations and the realities of the performance of the critical ESF indicators in Indonesia. The study involved 80 respondents of infrastructure project actors in Indonesia and found that 40% of the ESF indicators had performed well and met their expectations. Meanwhile, three indicators were inefficient or the performance exceeded the expectations, namely ESS6.3, ESS2.3 and ESS6.1. ESS7.2 and ESS8.1. This study is expected to contribute to developing a standardized and integrated ESF in Indonesia. Furthermore, the results of this study can be used as a consideration in further research, especially the use of the ESF variables as a moderator in modeling project social conflict.

Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters, namely, on the thermal conductivity and viscosity of aqueous salt solutions at temperatures of 293-473 K, pressures Ps = 100 MPa, and concentrations of 0-25 wt.%. Given the lack of data and models, especially for the dynamic viscosity of aqueous salt solutions at a pressure of above 40 MPa, generalized formulas are presented here, by which these gaps can be filled. The article presents a generalized formula for obtaining reliable data on the thermal conductivity of water aqueous solutions of salts for Ps = 100 MPa, temperatures of 293-473 K and concentrations of 0%-25% (wt.%), as well as generalized formulas for the dynamic viscosity of water up to pressures of 500 MPa and aqueous solutions of salts for Ps = 100 MPa, temperatures 333-473 K, and concentration 0%-25%. The obtained values agree with the experimental data within 1.6%.

As an archipelagic country with high cultural diversity, development projects in Indonesia are required to involve the community as a stakeholder appropriately. However, community engagement in the project is a dilemma where society can be a good supporter, while on the other side, it can be a risk factor. This research aimed to determine the type of project conflict that affects social conflict between the project and the local community and the impacts arising from social conflict. This study used 40 data on infrastructure projects in Indonesia collected from the questionnaire and analyzed using the Relative Importance Index (RII) method. This research revealed that value conflict was the most influential type causing social conflict, followed by affective, task-related, and rule-related conflicts. A personal relationship is the biggest impact caused by the project's social conflict, followed by the impact of cost, CSR, time, and the local workers' satisfaction. This research indicated that social values and norms still influenced the local community's life. Project managers can use these findings to develop conflict management strategies according to local socio-cultural conditions in order to reduce the potential for project-related conflict to escalate into social conflict. For further research, these results can be used as a reference in developing an appropriate environmental and social framework under the socio-cultural conditions of the Indonesian community; thus, social conflicts can be avoided, and project performance can be achieved according to the specified goals.