Korea and EU governments are running the tyre labelling system from 2012. All tyres sold in Korea have to carry a label displaying information about two performance criteria such as rolling resistance and wet grip. The rolling resistance of tyres determines their fuel efficiency grading and the wet grip of tyres determines their braking safety grading. Measurement of rolling resistance and wet grip must be reproducible; tests on the same tyres in different laboratories must produce the same results in order to ensure a fair comparison between tyres from different suppliers. In addition, a good reproducibility of testing results prevents market surveillance authorities from obtaining different results from those of the suppliers when testing the same tyres. The laboratory alignment procedure of rolling resistance was developed and published as an EU Commission Regulation No. 1235 in 2011. But the laboratory alignment procedure of wet grip has not developed yet. So there are a lot of differences of wet grip test results among the test laboratories in the world. The proposed new procedure for the alignment of test laboratories with regard to the measurement of tyre wet grip can improve the reproducibility of the wet grip testing results. The proposed wet grip laboratory alignment procedure was verified through five laboratory alignment tests between KATECH and five test laboratories in the world.

Abstract-This research suggests the velocity controller with advanced smart cruise control (ASCC) with stop & go control considering the surface friction coefficient and applying a safety distance. A safety distance affects quality of cruise control. If a safety distance is too short, the probability to cause a collision gets greater whereas if it is too long, it can cause traffic congestion. Thus, calculating the optimal safety distance is very important. In this study, we used fitting functions to obtain a basic safety distance and then added the μ-safety distance, considering friction coefficient and relative velocity, to calculate final safety distance. We invented ASCC and stop & go control by considering velocity of vehicle to maintain the safety distance and relative velocity at the same time. Carsim was used for simulation and we found that while a vehicle with the velocity controller, calculating the velocity and location difference between preceding and following vehicles with four friction coefficients, it keeps a safety distance.

EU and Korea governments are running the tyre labelling system from last year. European tyre label displays the grade of three performance parameters (Rolling resistance, wet grip and outside rolling noise).and All tyres sold in Korea will have to carry a label displaying information about two performance criteria (Rolling resistance, Wet Grip). Wet Grip is an important measure of tyre safety. There is growing interest in the wet grip test which is regarded as the most important test item in the tyre label. The wet grip index calculated by wet grip test determines the wet grip rating categories. In this study, uncertainty factors of wet grip index (such as SRTT, test surface friction, static load and water depth) and their effects on the wet grip index are analyzed using the design of experiments. When the uncertainty factors were varied within the test regulation conditions, the variations of wet grip index are analyzed.

Korea and EU governments are running the tyre labelling system from 2012. All tyres sold in Korea have to carry a label displaying information about two performance criteria such as rolling resistance and wet grip. The rolling resistance of tyres determines their fuel efficiency grading and the wet grip of tyres determines their braking safety grading. Measurement of rolling resistance and wet grip must be reproducible; tests on the same tyres in different laboratories must produce the same results in order to ensure a fair comparison between tyres from different suppliers. In addition, a good reproducibility of testing results prevents market surveillance authorities from obtaining different results from those of the suppliers when testing the same tyres. The laboratory alignment procedure of rolling resistance was developed and published as an EU Commission Regulation No. 1235 in 2011. But the laboratory alignment procedure of wet grip has not developed yet. So there are a lot of differences of wet grip test results among the test laboratories in the world. The proposed new procedure for the alignment of test laboratories with regard to the measurement of tyre wet grip can improve the reproducibility of the wet grip testing results. The proposed wet grip laboratory alignment procedure was verified through five laboratory alignment tests between KATECH and five test laboratories in the world.

When the queue length of congestion vehicles in tunnel fire is extended beyond tunnel length, the capacity of smoke control system needs to be increased in line with ventilation resistance. However, the vehicle queue length is not defined , so a rational equation is necessary in current fire prevention guideline. This study is intended to propose an equation to calculate the queue length considering the number of vehicles in queue in tunnel fire and evaluate the applicability by tunnel length as well. When it comes to normal tunnel, it is necessary to compare the vehicle queue length with tunnel length up to the length of 1,200 m in a bid to avoid applying the vehicle queue length excessively in case of fire. As a result of evaluation of applicability to model a tunnel, saving the number of jet fan for smoke control appeared to be effective. Besides, quantitative approach to explain the vehicle queue length through the relationship between the percentage of large vehicles and tunnel length was presented. Consequently, when the queue length of the congestion vehicles exceeds the tunnel length in determining the capacity of smoke control system in case of fire, the number of vehicles beyond the tunnel length needs to be excluded from estimating the ventilation resistance by vehicles.