휴대용 휘도 측정기를 이용한 노면표시 재귀반사도 평가

김부일 한국도로학회 2021 한국도로학회논문집 Vol.23 No.2

PURPOSES : The retroreflectivity of pavement markings for road safety was evaluated. METHODS : Field tests of pavement markings, which are characters, symbols, crosswalks, and stop lines, but do not include line markings, were conducted using a portable retroreflectometer with the purpose of evaluating the retroreflectivity according to the type of pavement markings and roads. Furthermore, changes in retroreflectivity due to wheel passing and wet conditions were evaluated. Here, 192 test points for evaluating the retroreflectivity of pavement markings, 5 test points for evaluating reductions in retroreflectivity during conditions of wetness, and 28 test points for checking variability due to type of testing device were selected on major and minor arterial roads in Seoul. RESULTS : The average retroreflectivity of pavement markings measured in this study was 115.7 (mcd/m2·lux), which is lower than the minimum retroreflectivity required six months after installation but higher than the minimum remarking retroreflectivity required by Seoul city. The retroreflectivity of pavement markings measured on minor arterial roads was 69.1% of that on major arterial roads. The average retroreflectivity of pavement markings was reduced to 43.1% by wheel passing, which is below the remarking criterion. The average retroreflectivity measured on wet pavement markings was 43.7 (mcd/m2·lux), which is a ninth of that under dry conditions. The test results showed that retroreflectivity in the rain was much lower than the required value in the case of rain, which is 175 mcd/m2·lux, as issued by Seoul city. Compared with mobile retroreflectometers, a portable retroreflectometer produced 17% higher retroreflectivity based on the results of 28 test points. CONCLUSIONS : Based on the field tests, the retroreflectivity of pavement markings, i.e., characters, symbols, crosswalks, and stop lines, was higher than the average remarking criterion. However, the retroreflectivities of pavement markings passed by the wheel or in rain were lower than the remarking criteria. Considering that the remarking criteria in Seoul city are higher than those in Europe and the test results in this study indicate much lower values than those required in Seoul, further study is necessary to be able to properly modify the criteria for retroreflectivity.

축광 노면표시의 야간 시인성 평가를 위한 기초 연구

이용문,김상태,정왕성,김흥래 한국도로학회 2016 한국도로학회논문집 Vol.18 No.4

PURPOSES: In this study, we evaluated changes in the retroreflectivity and luminance of phosphorescent road line markings with changes in glass beads and line marking thickness. METHODS : The color of line markings affects their retroreflectivity. Using a chromaticity test, we conducted the analysis of whether phosphorescent road line markings adhered to the「 KS M 6080」standard. Then, we measured the dry retroreflectivity and wet retroreflectivity for various glass bead refractive indices. We conducted wet retroreflectivity test using the EN 1436 standard as the basis. We also conducted luminance tests for different glass bead refractive indices and line marking thicknesses. RESULTS : 1. Phosphorescent road line markings specimens satisfied the 「KS M 6080」standard. 2. In dry retroreflectivity test, phosphorescent road line markings sprayed with glass beads satisfied the national police agency standard (240 mcd/(m2₩Lux)). Wet retroreflectivity test results showed that except for one type of No.1 glass beads, phosphorescent road line markings specimens sprayed with glass beads of one type of No.3 and two types of No.1 satisfied the national police agency standard (100 mcd/(m2₩Lux)). 3. Phosphorescent road line markings had higher retroreflectivity than non-phosphorescent road line markings in the dry condition. 4. Phosphorescent road line markings sprayed with glass beads demonstrated improved luminance. Luminance increased with higher glass bead refractive index and with increased line marking thickness. However, when the thickness crossed a certain threshold, phosphorescence ceased to increase; this is a characteristic of the phosphorescence phenomenon. CONCLUSIONS : Visibility across short distances can be ensured when phosphorescent road line markings are sprayed with glass beads, because of the retroreflection phenomenon. It is also possible to ensure far visibility using phosphorescent road line markings.

차선테이프의 재료별 성능평가를 통한 현장적용 연구

안덕순 한국도로학회 2021 도로 : 도로학회지 Vol.23 No.3

PURPOSES : The purpose of this study is to preliminarily examine the field applicability of modular pavement marking tape (PMT) to increase the lane awareness of motorists on existing roadways. METHODS : A pavement marking tape (PMT) comprises an adhesion layer and a paint coating layer. The adhesion layer is prepared using gussasphalt-based materials that have properties similar to those of existing asphalt materials. Thermal adhesion is performed to adhere the tape to the pavement. For the paint coating layer, polyurea materials are selected after reviewing the existing materials suitable for pavement lane marking. To conduct field evaluations on the adhesion layer, monitoring is performed after the pilot deployment of the PMT is completed. Twelve samples are prepared to investigate the optimal ratios for the mixture of paint coating layer materials. The durability of the PMT is examined using a turntable road-marking test system (RPA) with a wheel load on the samples. A total of 50,000 RPA, equivalent to P4, is performed. The performance is evaluated by capturing the retroreflectivity measure, which is used as an indicator of the pavement marking performance. The PMT is utilized on a roadway segment with significant heavy vehicle traffic, and continuous monitoring is performed to examine its performance in the field. RESULTS : Based on a visual inspection of the adhesion layer material, no significant issue is observed in terms of the adhesion performance of the PMT. Furthermore, the overall retroreflectivity obtained from the RPA exceeds 300 mcd/m2·lux. It is discovered that the optimal ratios for the mixture of polyurea and binder for the paint coating layer are 4:6 and 2:8, respectively, which results in a retroreflectivity that is 90% or above the initial retroreflectivity. Using a prototype of the PMT for field tests, a performance evaluation is conducted by analyzing the retroreflectivity measured after 2 and 7 weeks from the prototype deployment. The retroreflectivity measured for the first 2 weeks after the deployment appears acceptable for field use. However, the retroreflectivity is reduced significantly when it is measured 7 weeks after deployment, resulting in the necessity for a more reliable material that can retain long-term durability. CONCLUSIONS : The lane awareness of a motorist is crucial for accident mitigation under not only nighttime driving, but also severe weather conditions. In this regard, modular PMT is expected to increase the lane awareness of motorists, thereby improving the quality of lane marking materials. In this study, various exploratory field tests are conducted to analyze the field applicability of the PMT. It is noteworthy that the results presented herein are obtained from preliminary performance evaluations of the PMT. Hence, further investigations pertaining to the long-term durability of PMTs must be conducted using advanced test equipment such as an accelerated pavement tester.

차선테이프의 재료별 성능평가를 통한 현장적용 연구

안덕순 한국도로학회 2021 한국도로학회논문집 Vol.23 No.6

PURPOSES : The purpose of this study is to preliminarily examine the field applicability of modular pavement marking tape (PMT) to increase the lane awareness of motorists on existing roadways. METHODS : A pavement marking tape (PMT) comprises an adhesion layer and a paint coating layer. The adhesion layer is prepared using gussasphalt-based materials that have properties similar to those of existing asphalt materials. Thermal adhesion is performed to adhere the tape to the pavement. For the paint coating layer, polyurea materials are selected after reviewing the existing materials suitable for pavement lane marking. To conduct field evaluations on the adhesion layer, monitoring is performed after the pilot deployment of the PMT is completed. Twelve samples are prepared to investigate the optimal ratios for the mixture of paint coating layer materials. The durability of the PMT is examined using a turntable road-marking test system (RPA) with a wheel load on the samples. A total of 50,000 RPA, equivalent to P4, is performed. The performance is evaluated by capturing the retroreflectivity measure, which is used as an indicator of the pavement marking performance. The PMT is utilized on a roadway segment with significant heavy vehicle traffic, and continuous monitoring is performed to examine its performance in the field. RESULTS : Based on a visual inspection of the adhesion layer material, no significant issue is observed in terms of the adhesion performance of the PMT. Furthermore, the overall retroreflectivity obtained from the RPA exceeds 300 mcd/m2·lux. It is discovered that the optimal ratios for the mixture of polyurea and binder for the paint coating layer are 4:6 and 2:8, respectively, which results in a retroreflectivity that is 90% or above the initial retroreflectivity. Using a prototype of the PMT for field tests, a performance evaluation is conducted by analyzing the retroreflectivity measured after 2 and 7 weeks from the prototype deployment. The retroreflectivity measured for the first 2 weeks after the deployment appears acceptable for field use. However, the retroreflectivity is reduced significantly when it is measured 7 weeks after deployment, resulting in the necessity for a more reliable material that can retain long-term durability. CONCLUSIONS : The lane awareness of a motorist is crucial for accident mitigation under not only nighttime driving, but also severe weather conditions. In this regard, modular PMT is expected to increase the lane awareness of motorists, thereby improving the quality of lane marking materials. In this study, various exploratory field tests are conducted to analyze the field applicability of the PMT. It is noteworthy that the results presented herein are obtained from preliminary performance evaluations of the PMT. Hence, further investigations pertaining to the long-term durability of PMTs must be conducted using advanced test equipment such as an accelerated pavement tester.

도로환경에서 차선반사도 성능의 영향변수에 따른 특성

오흥운(Oh Heung-Un) 대한토목학회 2007 대한토목학회논문집 D Vol.27 No.3D

차선반사도의 성능은 교통사고 감소와 교통용량, 차량속도의 일정 유지와 밀접한 관련이 있는 것으로 알려져 있다. 본 논문에서는 전국의 시간적, 공간적으로 샘플링된 차선반사도 데이터 베이스 자료를 이용하여 차선 반사도 성능의 영향변수별 특성에 대하여 밝히고자 하였다. 현재 인간공학적 허용치에 대하여 고속도로의 경우 백색, 황색에 대하여 각각 110, 90 mcd/㎡/lux으로 정해져 있으나 관찰된 결과는 인간공학적 허용치를 균일하게 만족시키지 않는 것으로 나타났다. 영향변수인 12개월 변화, 일평균교통량에 따라 그리고 가열형, 내마모성, 변성아크릴, 수용성, 융착식과 같이 재료별로 인간공학적 최소치와 차이가 있음이 관측되었다. 본 논문을 통해 차선반사도 영향변수와 관련된 사항을 추론할 수 있다. 첫째 현재 영향변수별로 관측된 차선반사도가 인간공학적인 최소반사도와 차이가 있으므로 최소치와 관찰차이를 줄일 수 있는 개선형 인간공학연구나 재료시험연구가 필요하다. 둘째, 영향변수의 하나인 교통량이 많은 곳에서 관측된 차선반사도의 감소가 심하므로 그 적정유지방법에 대한 연구가 필요하다. 셋째 영향변수의 하나인 재료적 특성 성능과 인간공학적 최소반사도 성능이 차이가 나므로 재료별 차별적 사용방법을 검토해야 한다. 넷째, 관찰된 차선반사도의 영향변수별 표준편차가 매우 심한 것으로 확인되었다. 따라서 차선 성능의 교통시설물로서의 일관성 유지 방안이 추가로 심도 있게 연구 되어야 한다. Retroreflectivity is known to be correlated to levels of traffic capacity or uniformity of vehicle speeds. The present paper uses the nation wide data base of freeway retroreflectivity then tries to single out the characteristics of retroretlectivity according to levels of influencing factors. Currently, the ergonomic and allowable minimum retroreflectivity for Korean freeway is 110 and 90 mcd/㎡/lux for the white and the yellow pavement marking, respectively. It was resulted that observed values do not satisfy the minimum value uniformly. Following levels of influencing factors such as changes by 12 months, annual daily traffic, and material characteristics such as thermoplastic, durable, epoxy, water-borne, and solvent-borne paint, the observed values shows gaps from the minimum values. Consequent conclusions maybe be inferred. First, as observed shows gaps from the minimum values, there should be ergonomic and materialistic study performed for narrowing the gaps. Secondly, for the higher traffic volume road section, there should be countermeasures to maintain uniformity of retroreflectivity. Thirdly, as it is found out there is gaps between observed and ergonomic minimum retroretlectivity, there should be proper ways case by case to choose the materials of pavement markings before painting works. Fourth, as standard deviations of observed retroreflectivity for all influencing factors are considerable, ways to sustain uniformity as one of traffic control devices should be studied.

유리알 굴절률 변화에 따른 노면표시 초기 재귀반사도 평가

전성일,노재면,한승연,이문섭,김대곤 한국도로학회 2023 한국도로학회논문집 Vol.25 No.6

PURPOSES : The purpose of this study is to verify the effect of improving the retroreflectivity of pavement marking by increasing the refractive index of glass bead. METHODS : Pavement marking test-beds has been installed in National Highway 19, 42 and KICT Yeoncheon SOC Center. In testbeds several marking sections were installed for each type of marking materials and glass beads. In this test-beds initial dry and wet retroreflectivity were measured and analyzed. RESULTS : When the refractive index of glass bead was adjusted upward in water based paint(glass bead No.1→ No.2), dry retroreflectivity increased by about 30 to 70%, and wet retroreflectivity slightly increased by about 10 to 40%. When using glass bead No. 2 in water based paint, it was found to meet the standards of the Road Traffic Act. However, since wet retroreflectivity of water based paint slightly exceeds the standard value, a follow-up investigation is needed to determine how long this performance can be maintained. When using glass bead No.1 in MMA(methyl methacrylate), the average wet retroreflectivity was evaluated to be 128 to 150 mcd/lx/m2, and when using glass bead No.2, the average wet retroreflectivity was evaluated to be about 200 to 270 mcd/lx/m2. Accordingly, MMA showed the best performance compared to other paints. CONCLUSIONS : When using glass bead No.1 in water-soluble paints and thermoplastic, it did not meet the wet retroreflectivity standards of the Road Traffic Act. But when using glass bead No.2, it met the wet retroreflectivity standards. As a result of analyzing the road marking budget according to the upward adjustment of the refractive index of glass bead, it was analyzed that if only the material class was adjusted upward, the cost would increase by more than twice the current budget. In order to decrease this budget increase rate(to increase service life), it is necessary to strengthen quality control standards for pavement marking and develop scientific-systematic quality control techniques.

도로 노면 표시에 대한 라이다 강도와 재귀반사도 상관관계 분석

이준식,김기덕,전원기,차현우,이현종 한국도로학회 2023 한국도로학회논문집 Vol.25 No.6

PURPOSES : This project aims to measure the retroreflectivity (Intensity value) of road surface markings based on LiDAR and develop algorithms for deriving and analyzing retroreflectivity influence factors through regression analysis. METHODS : An experimental road lane was created to examine the trends of retroreflectivity and LiDAR intensity values, and a controlled indoor experiment was conducted to identify influencing factors. The optimal algorithm was developed by regression analysis of the experimental data. RESULTS : The significance probability (P-value) through SPSS linear regression analysis was 0.000 for measured height, 0.001 for perpendicular angle, 0.157 for vertical angle, and 0.000 for LiDAR intensity, indicating that measured height, vertical angle, and LiDAR intensity are significant factors because the significance probability is less than 0.05, and vertical angle is not significant. The NNR regression model performed the best, so the measurement data with height (1.2m, 2m, 2.2m) and vertical angle (11.3°, 12.3°, 13.5°) were analyzed to derive the optimal LiDAR Intensity measurement height and vertical angle. CONCLUSIONS : For each LiDAR measurement height and vertical angle, the highest correlation between LiDAR Intensity and retroreflectivity was found at a measurement height of 1.2 meters and a vertical angle of 12.3°, where the model learning accuracy (R2) was the highest.

도로 노면표시용 재생 유리의 반사성능에 관한 실험적 연구

이명수,전찬기,박정준 한국재난정보학회 2008 한국재난정보학회 논문집 Vol.4 No.2

재귀반사도 개선을 위한 MMA계 열경화성 차선도료의 설계

이승범 ( Seung Bum Lee ),이창근 ( Chang Geun Lee ),홍인권 ( In Kwon Hong ) 한국공업화학회 2015 공업화학 Vol.26 No.4

Several attempts to design the best-available thermosetting road markings by using MMA to improve the durability and retroreflectivity are presented in this paper. In order to improve field applicability, the components of main materials were designed by means of reducing the hardening time lower than eight minutes. The optimum mixing ratio of thermosetting road marking was TSRM-6 composed of 15.6 wt% of MMA monomer (Tg = 105 ℃), 6.0 wt% of PMMA (MW = 70,000, Tg = 60 ℃) and 1.2 wt% of TMPTA (MW = 338, Tg = 27 ℃). Also the homogeneous mixing of all components was necessary. The use of ceramic glass beads with an optimized TSRM-6 exhibited excellent performance by achieving retroreflectivity coefficients of 431, 354 and 172 mcd·m-2·lux-1 for dry, wet and rainy test condition, respectively at two hundred thousand cycles.

열가소성 차선도장에서 반사유리알의 함침특성

홍인권 ( In Kwon Hong ),이창근 ( Chang Geun Lee ),이승범 ( Seung Bum Lee ) 한국공업화학회 2015 공업화학 Vol.26 No.2

Thermoplastic road markings are one of the most widely used road markings in the world. However, the durability of domestic road markings is relatively shorter than that of the global average of, approximately, three years. To overcome it, the conventional thermoplastic road markings were prepared by adding polyolefin and oxidized PE wax to conventional petroleum resin. In addition, the melting viscosity was designed below 500 cP at 220 ℃ as well as the optimum viscosity for spray painting, and embedding ratio of glass beads were controlled about 50∼60% by spraying in an interval of 1 second. Also the glass bead adhesive ratio was improved by reducing the amount of CaCO3 below 40 wt%. The retroreflectivity was tested under four different conditions to evaluate the abrasion resistance of thermoplastic road markings. The retroreflectivity coefficient satisfied the international standard (150 mcd?m-2?lux-1) in this study, and TPRM-7 was determined as an optimal ratio.