PURPOSES : In this study, we examined the installation and the effect of the s-type approach lane marking near the stop line of a typical intersection access road. We examined the possibility of installation and standardization of this facility and its impact on vehicular speed management and carbon emission reduction. METHODS : To review the installation and standardization possibilities, the geometric size of the marking was set. The possibility of standardization was examined by applying it to lane markings. The velocity before and after the installation of the marking was compared and analyzed through the velocity estimation equation to assess the impact on speed management. Carbon emissions were estimated by comparing the emissions before and after applying the marking. RESULTS : The s-type approach lane marking can be installed near the stop line of the intersection access road. It was possible to standardize the lane marking by suggesting a formula to determine the size of the geometry. Additionally, the marking enabled vehicular speed management and improvement in the carbon yield. The marking decreased speeds by approximately 10 km/h, from the original speed of 36 km/h to 25.5 km/h after installation. The standard deviation per vehicle was reduced by approximately 5.9 km/h, from 5.8 km/h to 0.9 km/h. Additionally, carbon emissions decreased by 17%, from 14.1 g/40 m to 11.7 g/40 m. CONCLUSIONS : The geometry and size of the lane marking installation can be set near the stop line of the approach road. Standardization of this facility was also possible. The s-type lane marking, installed at the stop line of the approach road, has the potential to control the speed, reduce the acceleration or deceleration, and reduce the carbon emission. In the future, it is expected that such lane markings can be applied to multi-faceted areas

PURPOSES : The purpose of this study is to find out how to perform a visual-based conjoint analysis of signs, specifically for those in subway systems. METHODS: To identify the current problems with signs, we conducted installation case studies on subway signs and developed visualized materials for survey. The visualized survey cards were used to record the subjects’preferences in the conjoint analysis. RESULTS: Based on the current problems of sign, we developed the profile cards and used the visualized survey cards to conduct the survey for conjoint analysis. From the conjoint analysis using the visualized survey cards, it was found that the values of Pearson’s R and Kendall’s tau are close to 1. This suggests that our model is a very fitted model for conjoint analysis. CONCLUSIONS: We concluded that a conjoint analysis of subway signs could be reliably performed by using visualized survey cards.

PURPOSES : This study aims to propose widths of pedestrian zones considering the characteristics of sidewalk areas, pedestrian volumes, and pedestrian density. METHODS : We derived a pedestrian zone formula considering the maximum pedestrian volumes, mean intervals between pedestrians (pedestrian density), occupancy widths of pedestrians, and average speed of pedestrians. We compare the widths obtained using the formula with the existing Korean standards. RESULTS: Considering the pedestrian volumes and density, the pedestrian zone widths of neighborhood main sidewalk areas are determined to be 1.4~4.5 m, whereas those of commercial sidewalk areas are determined to be 1.4~2.9 m. CONCLUSIONS: Existing Korean regulations and guidelines provide a uniform standard sidewalk width. However, this study proposed a formula for determining pedestrian zone widths considering pedestrian volumes, characteristics of the sidewalk area, and pedestrian density.

PURPOSES: The purpose of this study is to compare the lane curing time of natural drying and a lane drying device when painting lines on a highway. METHODS: The painting process was carried out in July 2015 and September 2015, respectively, for the Gimcheon IC - Gimcheon JC. After the painting, measurements were obtained three times at six measurement points located at 20 m intervals on the shoulder line and the dividing line. The curing time was measured for natural drying and drying using a lane drying device, and compared for different pavement types (asphalt, concrete) and paint types (waterborne paint, methyl methacrylate paint). RESULTS : The results of the lane curing time comparison on the highway are as follows. The combination of asphalt and methyl methacrylate paint cured more rapidly during both the natural drying and drying using the lane drying device. Finally, it was cured at least 32.2% and 40.7% faster when using a drying device than in natural drying. CONCLUSIONS: The comparison of lane curing time of the highway showed that the combination of asphalt and methyl methacrylate paint cured more rapidly when using both natural drying and a lane drying device.

PURPOSES: The purpose of this study is to compare the consistency of widths by analyzing the current situation of the sidewalk in Korea and Japan Neighborhoods Area. METHODS: Literature on the sidewalk width of the Neighborhood Area is reviewed to compare the consistency of width. Through on-site surveys, We identify the current status of sidewalk in Korea and Japan. This compares the sidewalk width consistency in the Neighborhood Area. RESULTS : The width of whole sidewalks in Japan is ranged 330~445cm, which is lAvger than The width of whole sidewalks in Korea, ranged 237~420cm. Frontage Zone width is ranged 60~65cm in Japan, similar to 60cm in Korea. However, in Korea, there is a lAvge difference between Frontage Zone width and walking width average, and the standard deviation of width is lAvger than Japan. The Pedestrian Zone width is ranged 172~325cm in Japan, which is lAvger than ranged 0~295cm in Korea. The width of the Furniture Zone is ranged 135 ~ 331cm in Japan and lAvger than ranged 90~225cm in Korea. In Korea, the difference between the Furniture Zone width and the walking average width is small, and the standard deviation of width is smaller than that of Japan. CONCLUSIONS : In conclusion, the standard deviation of the frontage zone and the pedestrian zone width, which are included in the valid sidewalk width, The Korea is lAvger than in Japan. valid sidewalk width of Korea sidewalk is inconsistent. valid sidewalk width for wheelchair users does not meet the width of more than 2 meters.

PURPOSES : The purpose of this paper is to analyze the change in lane reflection performance through lane washing and sweeping on highway lanes. METHODS: This paper compared and analyzed the changes in lane reflection performance before and after lane washing and sweeping. The research method was as follows. First, we selected four research sites on the Gyeong-bu Highway. Second, the parameters affecting lane reflection performance are classified into luminance, brightness, and number of glass beads. Third, the change in reflection performance was measured after washing /sweeping at the same place after studying 60m of the unwashed/unswept area. Fourth, the measurement results were compared and analyzed before and after lane washing/sweeping. RESULTS: The results of this study are as follows. First, lane washing improved the luminance and brightness by 4.2~21.4% and 1.4~5.1%, respectively, and reduced the number of glass beads per wash by 0.2~1.2%. Second, lane sweeping improved the luminance and brightness by 2.3~8.5% and 0.8~2.3%, respectively, and reduced the number of glass beads per sweep by 0.8~4.9%. CONCLUSIONS : By comparing the results of lane washing and sweeping, it was found that compared to lane sweeping, lane washing improved the luminance and fewer glass beads were dropped.

근린지역 보도에는 표지판, 신호등, 가로수, 식수대, 변압기 등 여러 보도시설물들이 설치되어있다. 이러한 보도시설물들은 대부분 보도 진행방향의 좌측에 설치된다. 하지만 보도시설물들이 설치되는 면적을 과도하게 차지하거나 연석에서의 이격거리가 불규칙하게 설치되는 등으로 인해 보도총폭 중 보도시설물의 설치공간이 차지하는 비율이 증가한다. 이로 인해 유효보도폭이 감소하게 되고 보도의 주기능인 보행이동성과 편리성의 저하에 영향을 미치게 된다. 본 연구의 목적은 FHWA에서 제시하는 Zoning을 이용하여 국내와 일본 보도의 도로완충존(Furniture Zone)과 유효보도폭(Pedestrian Zone + Building Frontage Zone) 비를 비교하는 것이다. 도로완충존과 유효보도폭 비를 비교하기 위해 국내 근린지역 4구간, 일본 근린지역 4구간의 보도폭을 조사하였다. 조사한 자료를 가지고 FHWA에서 제시하는 Zoning을 이용하여 국내와 일본의 근린지역 보도의 Zone을 구분한다. Zone구분 후 도로완충존과 유효보도폭의 비를 구하고 일본과 국내를 비교분석한다. 일본 4개지점의 Zone구분 결과, 도로완충존폭과 유효보도폭의 비는 최소 0.87에서 최대 1.87으로, 최소값에 해당하는 지점을 제외하면 모두 1.55이상의 값을 가진다. 국내의 Zone구분 결과, 보도총폭과 유효보도폭의 비는 최소 0.30에서 최대 2.65으로 최대값에 해당하는 지점을 제외하면 모두 0.96이하의 값을 가진다. 일본의 근린지역 도로완충존과 유효보도폭 비는 최소값을 제외하고 1.5이상으로 도로완충존보다 유효보도폭을 더 많이 확보하고 있다. 하지만 국내의 경우 최대값을 제외하고 0.96이하로 도로완충존보다 유효보도폭이 작다. 이는 지나친 도로완충존 확보로 보도폭 사용이 비효율적인 것으로 판단된다.

PURPOSES: This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

PURPOSES: In this paper, the effectiveness of speed-maintained standardization in road geometry on environmental impact at a downward slope location, based on greenhouse gas (GHG) emission indicators, was studied. Specifically, the aim of this study was to ascertain whether speed-maintained standardization resulted in decreased CO2 emissions as well as noise pollution, due to reduced vehicle speeds. METHODS : In this study, speed-maintained standardization in road geometry was proposed as a means to reduce vehicle speeds, with a view to reducing CO2 emissions and noise pollution. This technique was applied at a downward slope location. The vehicle speeds, CO2 emissions, and noise levels before and after application of speed-maintained standardization were compared. RESULTS: It was found that speed-maintained standardization was effective as a means to reduce speed, as well as CO2 emissions and noise pollution. By applying speed-maintained standardization, it was confirmed that vehicle speeds were reduced consistently. As a result, CO2 emissions and noise levels were decreased by 9% and 11%, respectively. CONCLUSIONS : This study confirmed that speed-maintained standardization in road geometry is effective in reducing vehicle speeds, CO2 emissions, and noise levels. Moreover, there is further scope for the application of this method in the design of roads in urban and rural areas, as well as in the design of highways.

PURPOSES: Recently, many local governments have applied chicanes for traffic calming to ensure environment-friendly comfortable and safe roads. However, the geometry of a chicane is designed for speed reduction using a curved portion. This study aims to improve the road geometry conditions of chicanes for reducing carbon emissions and maintaining appropriate driving speeds by considering the relationship between road geometry and carbon emissions. METHODS: This study was conducted as follows. First, carbon emissions corresponding to changing acceleration of vehicles were studied. Second, vehicle acceleration caused by the relationship between the curve radius and the straight length was studied. Accordingly, desirable conditions of curve radius and length of the straight section for reducing carbon emissions were proposed. RESULTS: The existing literature on chicanes present the minimum value of stagger length and path angle in the primary variable condition. This study suggests the maximum values of the curve radius and length of straight section in the primary variable condition. Therefore, if a vehicle’s speed at a chicane is 30 km/h, this study suggests a curve radius of up to 24 m. In addition, if the vehicle’s speed is 24 km/h, this study suggests a length of straight section of up to 6.6 m. These are the geometric conditions for considering the control of acceleration to the vehicle’s maximum speed. CONCLUSIONS: This paper proposes an application of geometric conditions to reduce carbon emissions and maintain appropriate speeds of vehicles through a combination of curve radius and length of straight section.

PURPOSES: The present study aims to evaluate the added CO2 emissions incurred from accelerating operation when to increase the speed up to the allowed level. METHODS : The methodology used are basically the relationship between emission rates and vehicle speeds or acceleration rate. These rates together are used to calculate the added CO2 emissions incurred from accelerating operation. RESULTS: It was resulted that the all the emission rates are increasing proportionally to vehicle speeds or acceleration rates. Additionally, it was also resulted that allowable speeds increasing, the added emission rates are increasing rapidly. CONCLUSIONS: It may be concluded that if the allowable speed ranges are managed, CO2 emissions during vehicle operation are much reduced. From this reason, it was found that the allowable speed during highway design and operation would be much necessary

PURPOSES : This study aims to evaluate the road safety of the super-elevation transition section of a left turn curve and suggest the minimum longitudinal grade of a super-elevation transition section to be used before and after a left curved section. METHODS: We evaluated the road condition by means of the safety-criterion-evaluation method involving side friction factors, and then solve the problem by introducing the minimum longitudinal grade criterion based on conditions described in the hydraulics literature. RESULTS : It was calculated that when a road satisfies hydroplaning conditions, the difference between side friction assumed and side friction demanded is less than - 0.04. In this case, the safety criterion for the condition is unsatisfied. Conversely, when a road is in a normal state under either wet or dry conditions, it was calculated that the difference between side friction assumed and side friction demanded is more than 0.01. Thus, the safety criterion for this condition is found to be satisfied. After adjusting the minimum longitudinal grade applied to a super-elevation transition section, the hydroplaning condition can be eliminated and the safety criterion can be met for all sections. CONCLUSIONS : It is suggested that a minimum longitudinal grade should be provided on super-elevation transition sections in order to prevent hydroplaning.

PURPOSES : It is well known that experts determined the current standard dimensions of freeway lane markings. However, rigorous engineering rationale could be insufficient regarding whether or not the standard dimensions account for how visible the markings are to the driver. In this study, we seek to optimize the dimensions of freeway lane markings to improve their visibility to drivers. METHODS: The study was conducted as follows. First, alternative lane marking dimensions were selected which could be installed in a test construction site. Second, a video recording was made while driving on the test construction site. Third, subjects were shown the recorded video and then instructed to indicate their preference from among the various lane markings. Lastly, t-tests were applied to assess the statistical significance of differences in the preferences expressed. RESULTS : According to the t-test results, there was no significant difference in the preferences expressed regarding the lane marking widths. However, with regard to the dimensions of freeway lane marking, which represents line marking lengths, gap lengths, and widths of marking, the subjects expressed a preference for specific dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm. CONCLUSIONS : In considering the dimensions of freeway lane markings and their relation to visibility by the driver, it was found that dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm.