CORRELATES OF SEAT BELT USE AMONG TURKISH FRONT SEAT OCCUPANTS SimSekoglu, &Ouml / zlem M.S., Department of Psychology Supervisor: Assoc. Prof. Dr. Timo Lajunen June, 2005, 79 pages This thesis included three separate studies, which were observational, interview and survey studies, on seat belt use among Turkish front seat occupants. The observation study investigated occupant characteristics and environmental factors affecting seat belt use. Seat belts were used significantly more among females and older occupants than among males and younger occupants / and on intercity roads, at weekends and in the afternoons than on city roads, at weekdays and in the evenings. The interview study investigated the common reasons for using and not using a seat belt in different trip types, qualitatively. Safety, situational conditions, habit and avoiding punishment were the commonly reported reasons for using a seat belt, while situational conditions, not believing the effectiveness of seat belt use, discomfort and no habit of using a seat belt were the commonly reported reasons for not using a seat belt, for most of the trip types. In the third study, seat belt use both on urban and rural roads were explained with the basic and extended Theory of Planned Behavior (TPB) models and Health Belief Model (HBM), using Structural Equation Modeling. Basic TPB model showed a good fit to the data, while extended TPB model and HBM showed a low fit to the data. Within TPB constructs, attitudes and the subjective norm had a positive and significant relation to intentions to use a seat belt. Results were discussed for their implications to traffic safety in Turkey, along with limitations of the study and suggestions for further studies.

Present thesis will concentrate on the attention to reduce the input of whole-body vibrations transmitted to test drivers in durability tests. On behalf of Volvo Cars, the purpose has been to develop a concept solution on the driver's seat. Solving this problem is significant due to test driver’s safety and theirs ergonomically conditions. This project is conducted as a Bachelor of Science thesis for the Innovation & design engineer program at Karlstad University.    The assignment is in collaboration with the research and development department Proving Ground Testing Group located outside Borås on their test facility, Hällered Proving Ground (HPG). Where they perform endurance tests on rough roads with complete vehicles. The main goal of this project is to increase the time drivers can actively drive the test cars each day, as well as reduce the exposure of whole-body vibration transmitted to test drivers.   The project has been carried out through the Engineering Design Process, which is a substantial model for working with creativity during product development. The report consists of a pre-study in areas like dynamic systems of vibration, ergonomics, previous research, benchmarking and seat structure. This was achieved by identifying the problem areas in an early stage. A number of concepts solutions were evaluated and compared according to implementability and realizability. The final decision was made on a concept, resulted in changing the current foam in the seat. Thereafter, it presents the evaluation of materials throughout the material database CES EduPack and through product research.     The last part of the report presents results from laboratory testings and a field test. The objective was to determine which arrangement provided the best isolation throughout different combinations of materials/products and material thicknesses. The result of the test showed that an increase of material thickness was the optimal solution. Polyurethane (PUR) foam is best suited for this and factors such as material properties and combination of materials has less or none impact on reducing whole-body vibrations. Therefore, the current foam can maybe be enough, but it needs to be evaluated further. This solution doesn't do any major changes to the cars specification and therefore the cars can be evaluated as before.   Further development is to build a prototype with thicker dimensions and implement it in a test vehicle. Subsequently verifying a decrease of exposure from whole-body vibrations, in the form of a real-life test. The solution is intended solely for test vehicles at Volvo’s endurance track facility at Hällered. The assignment was to facilitate working conditions for test drivers and make the work more efficient. The thesis purpose was to achieve a sustainable solution, according to Volvo Cars` requirements to reduce exposure from whole-body vibrations and this project is therefore fulfilled. It was important that the solution was easy to implement and can be applied on all platforms, correspondently be used on future test cars from Volvo.