Today, authorities responsible for the operation of highways aim to provide comfort to road users as well as safety while driving. While driving, the most important component that determines comfort for road users is the pavement. The relative effects of various surface distress types in bituminous, hot mixed asphalt pavements on the International Roughness Index (IRI) component—used to evaluate the present performance, and hence the comfort, of pavements—are determined in this study. The presence of only one type of surface distress is very difficult to achieve in practice, especially in regards to pavements where a high degree of deterioration is observed. The presence of different types of surface distress in road pavements, due to similar problems in very close positions and even in nested forms, makes it difficult to assess this issue. The relationships between surface distress and IRI have been modelled to overcome this challenge. To this end, the Multivariate Adaptive Regression Splines (MARS) modelling approach, which is very successful in investigating the relationships between a large number of independent variables and dependent variables, has been used. The sensitivities of the surface distress inputs are evaluated singularly by means of a model with 29 input variables calibrated using the pavement distress data collected in 3295 highway pavement sections. As a result of this analysis, the sensitivity of surface distress inputs collected, as an area, has been determined to have an effect on the increase in IRI. The results are interpreted with the help of figures and tables.

It is well known that pavement distress negatively affects the drivers and passengers of vehicles. Many studies report that foremost among these negative effects is the vibrations that form within the vehicle. Ride comfort depends on the human response to vibration and vehicle response to the road. The goal of this study was to investigate the effect of pavement condition index on ride comfort and to determine the threshold comfort limits for passenger cars on urban asphalt concrete pavements. The pavement condition index (PCI) was determined for pavement sections subject to different surface distress using the PAVER system. Ride (driving) speeds of 20, 30, 40 and 50 km/h were assessed on the same pavement sections to measure vibrational effects inside the vehicle and on the passenger seat. These measurements were then evaluated using the ISO 2631-1 standard in order to determine the a _wz values. Using the logistic regression technique, predictive model that took into account linguistic concepts for estimating ride comfort levels based on PCI values was developed. With the aid of this mathematical model, comfort threshold values were determined for each driving speed within an interval of 0–100 PCI. The study results indicated that increasing driving speed was generally associated with higher PCI comfort thresholds.

The study investigated the levels of whole-body vibration (WBV) that people travelling in the vehicle are exposed to when passing through potholes of standard defined sizes. Firstly, vibration measurements were made at different speeds in road profiles whose geometry is known with a passenger car. With the help of these data, a half-car dynamic model was calibrated, and vehicle responses were digitized. WBV values occurring in the seat surfaces of vehicles caused by pothole type deterioration, which have nine different sizes were dynamically simulated. Evaluations were repeated using profiles representing three road classes. In the simulation, vibration values were produced by changing speeds ten units between 10 and 50 km/h and the effects of ride speed on WBV were also taken into account. Vibration data were analysed using vertical weighted root-mean-square acceleration (aw), vibration dose value (VDV) and equivalent static compressive stress (Se) parameters defined in the ISO 2631 standard.

The study is aimed to mathematically model the relationship between the amount of whole-body vibration exposed in a passenger car type vehicle and the ride speed of the vehicle in the same section and the International Roughness Index (IRI), which is used as a pavement performance indicator. Vibration measurements were analysed according to the evaluation method determined in the ISO 2631 standard, and frequency-weighted root-mean-square acceleration (a_w) values were obtained in the vertical direction. Mathematical relationships between real measurement data performed in 1114 road sections were investigated using regression analysis, artificial neural networks (ANN) and Adaptive Neural Fuzzy Inference System (ANFIS) modelling techniques. The models' performance levels were determined using comparison metrics, and it was determined that ANFIS was the model with the best goodness of fit, with the regression coefficient 0.955, mean absolute error (MAE) 0.013, and root mean squared error (RMSE) 0.020. The threshold values affecting the ride comfort of IRI and the ride comfort values corresponding to the IRI limit values recommended by the Federal Highway Administration (FHWA) were determined through the ANFIS mathematical model. Then, a sensitivity analysis was conducted to determine the effects of a certain increase in the IRI value on discomfort.

One of the easiest and most efficient ways to control vehicle speeds is to create undulations perpendicular to the axis of the road. The types of undulations especially used for speed management on urban road networks are called speed control bumps (SCBs) and speed control humps (SCHs) according to their width. In general, the undulation geometry is a very important factor in changing the shock levels to which passing vehicles are exposed, and accordingly, in reducing the vehicle speeds. This study compares SCBs and SCHs with regard to human health risks using the whole-body vibration (WBV) components (VDV, ${\mathrm{S}}_{\mathrm{e}}$ , and $R$ ) to which vehicle drivers are exposed while passing over the undulations. Because SCBs and SCHs are usually preferred for use in urban road networks, experimental vibration measurements are conducted at 20, 30, 40, and $50\mathrm{km}/\mathrm{h}$ vehicle speeds. In order to demonstrate the effects of different vehicle types, vibration measurements are repeated in the same driver and undulation geometries with sedan, hatchback, and station wagon vehicles for each measurement speed. The evaluations use standard evaluation methods which are frequently preferred in the world in WBV analysis. Using these methods, vehicle type and vehicle speed effects are reciprocally evaluated considering SCB and SCH geometries with equal heights. Use of the SCHs appears to be more suitable for human health in traffic speed management.

In this study, the flood hazard of Corum province (Turkey) was investigated using the Analytic Hierarchy Process (AHP), which is one of the most popular Multi-criteria Decision Analysis (MCDA) methods, based on Geographic Information System (GIS). As a result of the AHP process, Corum province was categorized into five flood hazard classes: very high, high, medium, low, and very low. It was determined that 3% of the total area is under a very high flood hazard, and 25% is considered a high flood hazard. To assess the validity of the flood hazard map, the results were compared with the historical flood inventory. Our hazard map was compatible with the historical flood inventory, and our hazard map can now be used to estimate the areas that are threatened by possible floods. When the existing structural measures are overlapped with the hazard map in Corum, it is understood that a large part of the structural measures carried out to date have focused on the areas of very high and high flood hazard in the flood hazard map. Future structural measures and detailed studies should now address other areas identified as under threat in the flood hazard map. Our results suggest that the hazard assessment based on MCDA is suitable for flood hazard mapping.