Keiichi OGAWA a. Keywords: Bicycle, Cycling Space, Traffic Accident, Intersection 1. INTRODUCTION

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1 Comparative Analysis of Traffic Accident Probability Based on Location and Bicycle Travel Direction Considering Number of Intersections between Origin and Destination for Bicycle Users Keiichi OGAWA a a Department of Civil Engineering, College of Science and Engineering, Ritsumeikan University, 1-1-1, Noji-Higashi, Kusatsu, Shiga , Japan; kogawa@se.ritsumei.ac.jp Abstract: The increased probability that bicycles traveling on the right side of a sidewalk will suffer accidents is seen as justification for regulating the location and direction of bicycle travel in Japan. However, this high traffic accident probability level exists primarily at intersections and is not indicative of the overall probability that cyclists will become involved in traffic accidents between their origin and destination points. This study compares traffic accident probability levels when provisions have been made to restrict bicycles the left side of a street with situations where bicycles are allowed to travel on both sides, taking into account the number of intersections traversed between origin and destination points. As results, traffic accident probability might be higher than when travel is allowed on both sides if bicycle travel restricted to the left side by the road network configuration in the target area. Keywords: Bicycle, Cycling Space, Traffic Accident, Intersection 1. INTRODUCTION In recent years, bicycles have come to be reevaluated as an urban transport mode in Japan, and local governments are encouraging citizens to switch from cars to bicycles in order to reduce environmental loads. However, because there is insufficient space for cycling on many roads, and because road users are not adequately aware of bicycle traffic rules, many cyclists travel in a chaotic manner on sidewalks and roads. As a result, traffic accidents between pedestrians and bicycles, and between cars and bicycles at intersections, have become a problem. Various localities are therefore attempting to introduce policies aimed at reducing traffic accidents and traffic conflict by regulating the location and direction of bicycle travel. This includes policies aimed at shifting the location of bicycle travel from sidewalks to roadways by, for example, strictly enforcing the general rule those bicycles must travel on the roadway and by providing dedicated cycling space on the roadway. Additional efforts include separating pedestrian/cycle space on sidewalks and introducing one-way systems on cycle paths. The fact that traffic accident probability is predominantly high for bicycles traveling on the right side at intersections of main and minor roads is cited as justification for introducing policies of this type. However, this high traffic accident probability level exists primarily at intersections and is not indicative of the overall probability that cyclists will become involved in traffic accidents between their origin and destination points. With regard to cycling space, the rules on bicycle travel direction for both sides of the road will differ depending on the provision method and whether such regulations have been introduced. When provisions are made to establish left-side-only bicycle travel by providing dedicated cycle

2 lanes on roadways or one-way systems on sidewalks, the number of intersections traversed between origin points and destinations increases because cyclists often have to cross roads or take long detours to appropriate crossing points in order to comply with the regulations. Therefore, in order to examine the effect of specifying left-side-only bicycle travel, it is necessary to compare traffic accident probability between origin and destination points while considering the number of intersections traversed. Additionally, it is necessary to select an appropriate method of providing cycling space while remembering that detour distances and the number of intersections traversed will differ depending on the road network and the number of crossings in the relevant area. In previous research, the authors calculated and compared the probabilities of cyclists becoming involved in traffic accidents between their origin and destination points while focusing on the Tokyo Metropolitan Area and Takatsuki, Osaka Prefecture (Ogawa and Morimoto, 2012; Ogawa and Hayashi, 2013). However, since the findings obtained tended to vary depending on road network conditions in the target area, it was deemed necessary to compare multiple areas with different road network configurations in order to obtain a more general conclusion. This study calculates traffic accident probabilities by considering intersections traversed between origin and destination points via an examination of existing statistics. The results are then used to compare traffic accident probabilities when bicycles are restricted to left side only and when travel is permitted on both sides of the road. Figure 1 shows the flowchart of this study. Estimation of traffic accident probability at individual intersections Number of intersections between origin and destination Estimation of traffic accident probability between origin and destination Analysis of relationship between traffic accident probability and number of intersections traversed Analysis of relationship between traffic accident probability and bicycle travel direction rules Figure 1: Flowchart of this study There are many existing researches for the characteristics of bicycle traffic and safety evaluations of mixed traffic of pedestrians and bicycles in Japan (Yamanaka et al., 2001; Yamanaka et al., 2003; Yamanaka, 2005; Ogawa and Oshikawa, 2006; Motoda et al., 2013). However, in most of existing researches, traffic safety within each section and traffic safety at each intersection are analyzed separately. Therefore, traffic accident probability between origin and destination for bicycle users is not considered. This study aims to analyze the traffic accident probability between origin and destination for bicycle users. 2. PROBABILITY OF BICYCLE TRAFFIC ACCIDENTS AT INTERSECTIONS Cycling on the roadway is promoted by saying that it is generally safer than cycling on the

3 sidewalk, while cycling in the same direction as vehicle traffic is generally considered safer than cycling oppositely to vehicle traffic on roadways. Tables 1 and 2 are often cited in this regard (Matsumoto, 2009). Table 1: Occurrence of right-angle collisions between cars and bicycles at intersections where a minor road joins a main road ( ) (Matsumoto, 2009) Occurrence of right-angle collisions between cars and bicycles Roadway 0 Sidewalk (closest to Left-side travel roadway) Sidewalk (closest to private land) Roadway 1.5 Sidewalk (closest to Right-side travel roadway) Sidewalk (closest to private 0.73 land) (Unit: Accidents per million bicycles) Table 2: Occurrence of left-turn collisions between cars and bicycles at intersections where a minor road joins a main road ( ) (Matsumoto, 2009) Occurrence of left-turn collisions between cars and bicycles Roadway 0 Left-side travel Sidewalk Roadway 0 Right-side travel Sidewalk (Unit: Accidents per million bicycles) Tables 1 and 2 extract and consolidate bicycle accidents occurring between on a section of main road within the Tokyo metropolitan area (15.2 km) at all intersections where a minor road joins the main road. Of the 146 bicycle accidents during the four-year period, 89 were right-angle collisions, 40 were left-turn collisions, and 7 were rightturn collisions. Table 1 shows the locations and bicycle travel direction for right-angle collisions at intersections where a minor road joins a main road at times when a car coming from the minor road collides with a bicycle traveling along the main road. The number is traffic accident probability per million bicycles for each location and travel direction calculated using (12-hour) measured data on bicycle traffic volumes on the relevant road. The table shows that, on this section of road, traffic accident probability is high for bicycles traveling on the right side of the main road (opposite roadway travel direction) and for bicycles traveling on the right side of the sidewalk closest to the private land. Table 2 shows the location and direction of bicycle travel in left-turn collisions at intersections where a minor road joins a main road when a car that is turning left from the main road collides with a bicycle traveling along the main road. This table shows that the traffic accident probability for bicycles traveling on the left side of the sidewalk (roadway

4 travel direction) is relatively high. In Table 1, the probability of bicycle traffic accidents is lower and safety is improved for left-side travel (roadway travel direction), while in Table 2, the probability is lower and safety is better for right-side travel (opposite roadway travel direction). However, since the traffic accident probability values are higher for right-angle collisions in Table 1, by combining the two tables, we find that left-side travel is safer than right-side travel on both the roadway and the sidewalk. The section of main road within the Tokyo metropolitan area (15.2 km) used in Tables 1 and 2 is understood to be a section of National Route 254 in the Tokyo Metropolitan Area. Accordingly, to establish traffic accident probabilities in this study, the analysis described below was performed for a similar section of the same route. 3. BICYCLE TRAVEL DIRECTION AND NUMBER OF INTERSECTIONS TRAVERSED As described in the preceding section, existing research shows that traffic accident probability is high at individual intersections for bicycles traveling on the right side. However, this traffic accident probability exists at individual intersections and is not the probability of a cyclist being involved in a traffic accident between their origin and destination points. When provisions are made to establish left-side-only bicycle travel, such as by providing dedicated cycle lanes on roadways or establishing one-way systems on sidewalks, the number of intersections traversed between origin and destination increases because cyclists have to cross roads or take detours to approved crossing points in order to comply with the regulations. Therefore, in order to examine the effects of specifying left-side-only bicycle travel when providing cycling space, it is necessary to compare traffic accident probability between origin and destination points while taking into consideration changes in the number of intersections traversed. Figures 2 and 3 show the differences of the number of intersections traversed based on the bicycle travel direction rules. In case of Figure 3, number of intersections traversed increases if bicycle travel direction is restricted to the left side only. It is known that the differences of the number of intersections become large if the distance of two intersections of two main roads is large. Therefore, the relationship between traffic accidents probability and number of intersections depends on the ratios of the number of intersections of two main roads to the number of intersections of main and minor roads. Left side only Travel on both side possible Destination Origin Figure 2: Differences of the number of intersections traversed based on the bicycle travel direction rules (case 1)

5 Left side only Travel on both side possible Origin Destination Figure 3: Differences of the number of intersections traversed based on the bicycle travel direction rules (case 2) Figure 4 shows the images of cycling spaces in Japan. Generally, the methods of providing cycling space and bicycle travel direction rules in Japan are connected as follows: Roadway (with dedicated cycle lane): Left side only Roadway (without dedicated cycle lane): Left side only Cycle path: Travel on both sides possible Sidewalk (with lane markings): Travel on both sides possible Sidewalk (without lane markings): Travel on both sides possible However, even if the provided method makes it possible to travel on both sides, if a one-way system is introduced, travel will be left side only. Therefore, when making provisions to establish left-side-only bicycle travel, it is necessary to select a method that considers detour distances and intersections traversed, which will differ depending on the road network condition and the number of usable crossings. Roadway (Shizuoka) Cycle path (Nagoya) Sidewalk (Kusatsu) Figure 4: Images of cycling spaces in Japan This study calculates traffic accident probability between origin and destination points by taking into consideration the number of intersections traversed based on bicycle traffic accident probabilities at individual intersections. The results are used to compare traffic accident probabilities when bicycle travel is restricted to the left side only and when bicycles travel on both sides of a roadway. Although various conditions could have been set in this comparison, this study considers traffic accident probability at intersections of main and minor roads (as shown in the preceding section) while assuming that bicycles are traveling along the main road. Traffic accident probability at the intersections of two main roads assumes that bicycles are crossing one of the main roads. Additionally, in reality, when two-way bicycle travel is permitted, it is

6 possible for traffic accidents or conflicts (head-on collisions, collisions caused by cyclists avoiding each other, etc.) to occur due to the chaotic mixing of bicycles traveling in different directions on cycle paths or sidewalks. However, such accidents are outside the scope of this study. 4. TRAFFIC ACCIDENT PROBABILITY AT INDIVIDUAL INTERSECTIONS 4.1 Traffic Accident Probability at Intersections of Main and Minor Roads Tables 1 and 2, shown in the preceding section, are based on existing research and, in this study, are used for calculating traffic accident probability at intersections of main and minor roads (Matsumoto, 2009). 4.2 Traffic Accident Probability at Intersections of Two Main Roads In this study, data given in traffic accident maps published by the Tokyo Metropolitan Police Department are used to calculate traffic accident probability at intersections of two major roads. Since Tables 1 and 2 in the preceding section focus on National Route 254, this study calculates traffic accident probability for a section the same route. The traffic accident maps were created by the Traffic Bureau of the Tokyo Metropolitan Police Department using geographic information system (GIS) data. Traffic accident occurrences in the Tokyo Metropolitan Area can be easily viewed over the internet by accident density. Specifically, the maps use colors to separately provide traffic accident density for total traffic accidents, accidents involving motorcycles, elderly people, pedestrians, children, bicycles, and commercial vehicles. They also show traffic accident sites for each of these types using black dots. Traffic accident density is calculated using kernel density estimation. The number of accidents is tallied for each 100 m square cell together with the accidents circumstances. These data are then converted to number of accidents per square kilometer and displayed on the internet. With regard to bicycle traffic volume, this study uses values from measurement points in five places (Kohinata, Bunkyo ; Ikebukuro, Toshima ; Oyamanishicho, Itabashi ; Sakuragawa, Itabashi ; Narimasu, Itabashi ) on the National Route 254 section where bicycle traffic volumes were measured for the FY 2005 Road Traffic Census. Because bicycle traffic volumes were measured in the five places listed above, this study calculates traffic accident probability by dividing a section of National Route 254 (17.6 km) midway from the measurement points, and then calculating traffic accident probability for each of these five sections. Specifically, the number of traffic accidents per year at intersections in each section is determined from the bicycle accident sites in the first half of FY 2011 published in the 2011 Traffic Accident Map, and traffic accident probability per million bicycles is found by dividing by the annual bicycle traffic volume in the respective section from the FY 2005 Road Traffic Census. Since there are no data regarding the relationship between traffic accident occurrence and location and bicycle travel direction, traffic accident probability is taken to be the same regardless of location and travel direction. As examples, Figures 5 and 6 show the on-screen traffic accident maps for the sections of road in Kohinata, Bunkyo, and Ikebukuro, Toshima, respectively. Table 3 shows the number of bicycle traffic accidents in each section (including the other three sections) taken from the maps.

7 Figure 5: Occurrence of bicycle traffic accidents in Kohinata, Bunkyo Figure 6: Occurrence of bicycle traffic accidents in Ikebukuro, Toshima Table 3: Number of traffic accidents at intersections of two main roads Number of traffic accidents per year Kohinata, Bunkyo 5 Ikebukuro, Toshima 7 Oyamanishicho, Itabashi 3 Sakuragawa, Itabashi 1 Narimasu, Itabashi 1 Next, Table 4 shows the results of estimating the weekday/holiday bicycle traffic volume in each section obtained from the FY 2005 Road Traffic Census and the annual bicycle traffic volume in each section based on the number of weekdays and holidays per year.

8 Kohinata, Bunkyo Ikebukuro, Toshima Oyamanishicho, Itabashi Sakuragawa, Itabashi Narimasu, Itabashi Table 4: Annual bicycle traffic volume in each section Weekday (number of bicycles) Holiday (number of bicycles) Annual traffic volume (number of bicycles) 1,219 1, ,735 3,555 4,004 1,351,006 3,650 4,256 1,404,364 2,214 2, ,654 3,373 4,306 1,342,172 Based on Tables 3 and 4, Table 5 shows traffic accident probability per million bicycles by dividing the number of bicycle traffic accidents per year by the annual bicycle traffic volume in each section. Looking at this table, it can be seen that bicycle traffic volume is high in three sections: Ikebukuro, Toshima ; Oyamanishicho, Itabashi ; and Narimasu, Itabashi. However, traffic accident probability is highest in Kohinata, Bunkyo, and it is evident that as the sections approach the center of the Tokyo Metropolitan Area, traffic accident probabilities increase. Looking at the totals for the five sections, it can be seen that the number of traffic accidents per year is 17, the annual bicycle traffic volume is 5,442,931, and traffic accident probability per million bicycles is Table 5: Traffic accident probability at an intersection of two main roads Number of traffic accidents per year Annual bicycle traffic volume (number of bicycles) Traffic accident probability (accidents/million bicycles) Kohinata, Bunkyo 5 468, Ikebukuro, Toshima 7 1,351, Oyamanishicho, Itabashi 3 1,404, Sakuragawa, Itabashi 1 876, Narimasu, Itabashi 1 1,342, Total 17 5,442, Traffic Accident Probability at Individual Intersections Based on the results so far, Table 6 shows traffic accident probabilities at intersections of main and minor roads and at intersections of two main roads. Cycling on the right side of a roadway is prohibited, but it is included here for traffic accident probability comparisons between origin and destination points according to location and travel direction, which is described later.

9 Table 6: Traffic accident probability according to intersection/ location of travel Intersections of main and minor Intersections of roads two main roads Right-angle collision Left-turn collision Roadway 0 0 Sidewalk (closest to (closest to Left-side travel roadway) 3.12 Sidewalk private land) Roadway Sidewalk (closest to (closest to Right-side travel roadway) 3.12 Sidewalk private land) (Unit: Accidents per million bicycles) The table shows that traffic accident probability at individual intersections differs depending on the location and direction of bicycle travel. In addition, at intersections of main and minor roads, the traffic accident probability for bicycles traveling on the right side is high, but the traffic accident probability at intersections of two main roads is higher. This suggests that the number of intersections traversed influences traffic accident probability between origin and destination points. 5. TRAFFIC ACCIDENT PROBABILITY BETWEEN ORIGIN AND DESTINATION 5.1 Relationship between Traffic Accident Probability and Number of Intersections Traversed This section examines the relationship between traffic accident probabilities and number of intersections traversed between origin and destination points by assuming a hypothetical road network. Based on above analysis, traffic accident probability between origin and destination is estimated by the following equation. Where P is traffic accident probability between origin and destination. p1, p2, p3, n1, n2 and n3 are shown in Table 7. (1)

10 Traffic accident probability (accidents/million bicycles) Table 7: Traffic accident probability at individual intersections and number of intersections Traffic accident Number of probability at intersections between individual origin and destination intersections Intersections of two main roads p1 n1 Intersections where a minor road joins a main road Right-angle collisions between cars and bicycles Left-turn collisions between cars and bicycles First, it examines traffic accident probability according to location and travel direction. Here, because traffic accident probability between origin and destination points depends on both the number of intersections traversed on two main roads and the number of intersections traversed on main and minor roads, it is necessary to set the ratio of the two. Herein, we examine hypothetical cases for the ratio of the number of intersections of two main roads to the number of intersections of main and minor roads, which is set at 1:5 or 1:10. This assumes that detour distances and number of intersections traversed will differ depending on the road network state and the number of crossings in the target area, and that the frequency of intersections of two main roads where it is possible to cross the road will differ. Figures 7 and 8 show the relationship between traffic accident probability and number of intersections traversed according to location and travel direction when the ratio of number of intersections of two main roads to the number of intersections of main and minor roads is 1:5 and 1:10 respectively. Here, the values for traffic accident probability at individual intersections shown in Table 6 are used. p2 p3 n2 n Number of intersections of two main roads traversed Roadway: left-side travel Sidewalk (closest to roadway): left-side travel Sidewalk (closest to private land): left-side travel Roadway: right-side travel Sidewalk (closest to roadway): right-side travel Sidewalk (closest to private land): right-side travel Figure 7: Relationship between traffic accident probability and number of intersections traversed (main road: minor road = 1:5)

11 Traffic accident probability (accidents/million bicycles) Number of intersections of two main roads traversed Roadway: left-side travel Sidewalk (closest to roadway): left-side travel Sidewalk (closest to private land): left-side travel Roadway: right-side travel Sidewalk (closest to roadway): right-side travel Sidewalk (closest to private land): right-side travel Figure 8: Relationship between traffic accident probability and number of intersections traversed (main road: minor road = 1:10) From these figures, it can be seen that the calculated values for traffic accident probability are, of course, proportional to the values for traffic accident probability at the individual intersections shown in Table 6. However, by comparing these probabilities with one another, it is possible to compare changes in traffic accident probability due to differences in location and travel direction and changes in traffic accident probability due to differences in the number of intersections traversed. This makes it possible to compare traffic accident probability by taking into account the difference in the number of intersections traversed based on location and travel direction, which depends on the positional relationship between the origin and destination points and the road network state in the target area. 5.2 Relationship between Traffic Accident Probability and Bicycle Travel Direction Rules Next is examined the relationship between traffic accident probability and bicycle travel direction rules while assuming the realistic provision of cycling space and the introduction of a one-way system. When considering realistic cycling space and one-way system introduction, it is important to remember that bicycle travel may be specified as left side only, but not right side only. The decision then becomes whether to specify left-side-only travel or travel on both sides. Therefore, when comparing traffic accident probabilities between origin and destination points, it is necessary to make comparisons based on whether the bicycle travel direction is left side only or both sides. When cycling space is provided on a roadway, it is prohibited to cycle on the right side (against traffic direction), which means that right-side roadway travel does not need to be included when considering provision methods. On the other hand, when bicycles travel on sidewalks, they can travel on both sides, but a one-way system can also be introduced. Accordingly, it is necessary to compare both methods in order to determine the most advisable under the circumstances. In regard to realistic cycling space and one-way system introduction,

12 Traffic accident probability (accidents/million bicycles) the following three types of travel conditions are taken for comparison: Roadway: Left side only Sidewalk: Left side only (with one-way system) Sidewalk: Travel on both sides possible (without one-way system) The relationship between traffic accident probability and number of intersections traversed between origin and destination points is examined as in the preceding section for these three types of travel conditions. Here, traffic accident probability in the case of left-side travel on the roadway is the same as in Figures 7 and 8 in the preceding section. Meanwhile, since Table 6 establishes multiple traffic accident probabilities in regard to travel on a sidewalk, these mean values are used. More specifically, Table 6 establishes traffic accident probabilities for bicycles traveling on the sidewalk closest to the roadway and closest to the private land separately in the case of left- and right-side travel. However, here the mean values of both are used because the mean traffic accident probability is used for bicycle sidewalk travel. Additionally, for bicycle travel on both sides of the sidewalk, there is left- and right-side travel, and which case requires the greatest number of intersections to be traversed differs depending on the positional relationship between the origin and destination points. However, when various origins and destinations within the target area are assumed, the number of intersections traversed can be understood to be roughly equal, and so the mean value of both cases is used. Figures 9 and 10 show the relationship between traffic accident probability and number of intersections traversed between origin and destination points assuming realistic bicycle travel direction rules. As in the preceding section, the cases when the ratio of number of intersections of two main roads to number of intersections of main and minor roads is 1:5 and 1:10 are shown Number of intersections of two main roads traversed Roadway: Left side only Sidewalk: Left side only (with one-way system) Sidewalk: Travel on both sides possible (without one-way system) Figure 9: Relationship between traffic accident probability and bicycle travel direction rules (main road: minor road = 1:5)

13 Traffic accident probability (accidents/million bicycles) Number of intersections of two main roads traversed Roadway: Left side only Sidewalk: Left side only (with one-way system) Sidewalk: Travel on both sides possible (without one-way system) Figure 10: Relationship between traffic accident probability and bicycle travel direction rules (main road: minor road = 1:10) Both Figures 9 and 10 shows that when the number of intersections traversed is the same, traffic accident probability is lowest for bicycle travel on the left side of the roadway, followed by travel on the left side of the sidewalk, and then travel on both sides of the sidewalk. However, when detours must be made and roads crossed as a result of restricting bicycle travel to the left side, the number of intersections traversed will increase even if the origin and destination combination is the same. Therefore, it is possible that traffic accident probabilities will be higher than when both-side travel is allowed. This suggests that, depending on the state of the road network in the target area and the positional relationship between the assumed bicycle origin and destination, traffic accident probability could actually increase as a result of stipulating left-side-only bicycle travel. Additionally, comparing Figures 9 and 10, the difference in traffic accident probability for all three types of travel conditions is greater in Figure 10, where the number of intersections of two main roads is relatively small and there are few crossing points. This means that the relationship between traffic accident probability and bicycle travel direction rules, such as those mentioned above, differs depending on the road network in the target area. Therefore, when considering methods of providing cycling space, it is necessary to select the method best suited for the target area and to carefully ascertain the advisability of a one-way system. 6. CONCLUSION Based on the probabilities of bicycle traffic accidents at individual intersections shown by existing statistics, this study calculated traffic accident probabilities between origin and destination points while taking into account the number of intersections traversed. The results were used to compare traffic accident probability when provisions have been made for leftside-only bicycle travel and when bicycles are allowed to travel on both sides. These comparisons showed that when the number of intersections traversed is the

14 same, traffic accident probability is lowest for bicycle travel on the left side of the roadway, followed by travel on the left side of the sidewalk, and then travel on both sides of the sidewalk. However, when detours must be made and roads crossed as a result of restricting bicycles to the left side, the number of intersections traversed will increase even if the origin and destination combination is the same. Therefore, it is possible that traffic accident probability will be higher than when travel is allowed on both sides. This, in turn, suggests that depending on the state of the road network in the target area and the positional relationship between the assumed bicycle origin and destination, traffic accident probability could, in fact, increase as a result of restricting bicycle travel to the left side. These results shows that the decision to make the direction of bicycle travel left side only or to allow bicycle travel on both sides should take into consideration the road network configuration in the target area. The calculations in this study are limited to cases in which the ratio of intersections of two main roads to number of intersections of main and minor roads is set hypothetically, and cases where the ratio of number of intersections of two main roads to number of intersections of main and minor roads in the road networks are limited. Therefore, future studies will need to conduct calculations under conditions that assume more realistic road network states and road crossing possibilities. They must also more fully demonstrate the relationships between the road network states in specific target areas and decisions on most appropriate methods for providing cycling space, as well as the advisability of introducing a one-way system. ACKNOWLEDGEMENTS The author would like to thank Mr. Kazuhiro Morimoto and Mr. Shotaro Hayashi for help in surveying and calculation. REFERENCES Matsumoto, K. (2009) Present conditions and problems on cycling space -Forecasting bicycle accidents and safety design for the crossing-, Seminar of infrastructure planning, 54. (in Japanese) Motoda, Y., Usami, S., Takahashi, K., Gotoh, S. (2013) Study on direction of bicycle on sidewalk, Proceedings of infrastructure planning, 47, 370. (in Japanese) Ogawa, K., Hayashi, S. (2013) A comparative analysis of the traffic accident probability of bicycles considering traffic positions and directions of bicycles -Case study in Takatsuki -, Proceedings of infrastructure planning, 47, 371. (in Japanese) Ogawa, K., Morimoto, K. (2012) A comparative analysis of the traffic accident probability of bicycles considering the number of intersections between origin and destination for bicycle users, Proceedings of infrastructure planning, 46, 206. (in Japanese) Ogawa, K., Oshikawa, T. (2006) A study on application possibility of the traffic conflict indices to the phenomenon of bicycle traffic, Traffic science, 36, 2, (in Japanese) Takeda, K., Kaneko, M., Matsumoto, K. (2008) Analysis of bicycle accidents and examination of safety design for the crossing, Proceedings of infrastructure planning, 38, 94. (in Japanese) Yamanaka, H. (2005) Evaluation method of street environment for bicycles under a mixed traffic with pedestrians, Traffic engineering, 40, 5, (in Japanese)

15 Yamanaka, H., Handa, Y., Miyagi, Y. (2003) Evaluation method of shared use of bicycles and pedestrians using near-miss index and proposal of its level-of-service, Journal of infrastructure planning and management, 730, (in Japanese) Yamanaka, H., Tamiya, K., Yamakawa, H., Handa, Y. (2001) Evaluation index for mixed traffic of pedestrians and cyclists considering the bicycles speed, Infrastructure planning review, 18, (in Japanese)