Development of the security module for bicycles

Development of the security module for bicycles Dmytro Shtogryn dmytro.shtogryn@tecnico.ulisboa.pt Instituto Superior Técnico, Universidade de Lisboa, Portugal November 2016 Abstract The number of cyclist has been increasing every year in Portugal, as well as the number of accidents. The main goals of this work are: statistical study of accidents with cyclist in the period between 2010 and 2014, analysis of the results of the survey under the COST project and development of the low-cost prototype of the security module for bicycles that records potentially hazardous situations when the cyclist runs the transit route. Every year approximately 50 % of road accidents with cyclist are lateral and rear-end collision. These two types of accidents cause large numbers of victims serious injuries and fatalities, therefore overtaking maneuvers and the lateral distances between motor vehicle and velocipede should be studied. The core of such security module for bicycles is an electronic prototyping platform - Arduino. Two ultrasonic ranging sensors capture the distance between bicycle and motor vehicle in a range up to 4 meters. The prototype was tested on the national road and urban areas, as a result it was possible to verify its correct functionality. Were performed several paths in order to study the effect of helmet and position towards the lateral distance. After analysis of the records of the two tests performed on the national road, was found that drivers when performing overtaking maneuver left greater lateral distance in the case of cyclist with helmet. Taking into account the growing popularity of bicycles, the experiments with MSB can help create new measures of security. Keywords: Security Module for Bicycle, bicycle, road safety, lateral distance, overtaking, instrumented bicycle, Arduino 1

1 Introduction In the XXI century the tendency of practicing healthy lifestyle becomes increasingly popular among all communities. Thus, bicycles are becoming increasingly popular as well. The issue of a road safety has been actively discussed in recent years due to the rise in the number of vulnerable road users particularly cyclists. Cyclists make up to 8 % of all who die in road accidents in the European Union (EU) in total. The number of cyclist fatalities has decreased by only 3 %, which is much lower than the total fatality decrease of 18 % from 2010 to 2013 [1]. It is essential to analyze and understand the nature of the most frequent accidents, behaviour of motor vehicles drivers when they perform precarious manoeuvres that endanger cyclists, as well as to identify all risk factors. Such analysis could help to improve traffic conditions and increase road safety. The general situation regarding road accidents in Portugal is moving in proper direction, but not in the bicycles category, at least until 2015. There were recorded 31953 road accidents in 2015 (4,4 % more than in 2014), however there was a significant decrease in the number of fatal accidents from 603 in 2014 to 554 accidents in 2015 (-8,1 %) [2]. In relation to bicycles the situation is almost similar, if to compare 2014 and 2015, a quantity of accidents increased, as well as the number of victims (+ 100 victims), while the part of fatal victims decreased from 35 to 25 occurrences. The scenario is not as serious as in other European countries, for example in Latvia or in France, but it is still necessary to develop and implement road safety measures, in particular applied to the two-wheelers. In order to develop new and efficient measures, it is recommended to conduct a study of some past accidents and analyze the current traffic conditions on public roads. With an aim to improve lives of cyclists by making them more secure and invulnerable, the security module for bicycles MBS (in Portuguese: Módulo de Seguranca para Bicicletas) will collect data about the free distances (lateral and rear) left by motorized vehicles on shared routes. A conflict between cyclists and motor vehicles exists because of shared roads on the one hand, and on the other hand we have conflicts between cyclists and pedestrians due to the lack of special bicycles paths [3], both of them should be resolved. 2 Statistical analysis of accidents with bicycles in Portugal Around 7000 accidents during a period between 2010 and 2014 were studied throughout this analysis. As it was mentioned before, the number of accidents with bicycles increases, so it is important to figure out the most frequent reasons of accidents and understand their origin. After analysis of thousands of accidents following conclusions can be made: average age of victims is between 38 and 41 years; 2

around 11-13 % of victims are female drivers; the most frequent accidents are lateral and rear-end collisions; the number of victims with helmet in 2014 is 80 % greater than in 2011; 92% of accidents were reported during good weather; 30% of all fatal victims are casualties of night accidents; Aveiro, Lisbon and Faro are three districts with bigger indicators of accidents and victims; within localities happened around 87 % of all accidents. All conclusions mentioned before are important, but for the present study we will focus on the point number 3 (collisions) and number 6 (night accidents). Regarding nature of the accident, more than a half of all cases are results of collisions, particularly side and rear. The distribution of the percentage of the side impact accident and rear-end impact during 2010-2014 shown in Figure 1. As can be seen, every year around 40 % of accidents are side impact ones with other motor vehicle, however since 2012 a reduction was achieved related to such accidents. The MBS prototype can warn drivers about the proximity of other vehicles, both at the rear and the side cases. All data about overtaking maneuvers can be further studied to determine possible factors that influence behaviour of motor vehicle drivers during the overtaking maneuver. Figure 1: Percentage of lateral and rear-end collisions during 2010-2014 As has been shown above, collisions with other motor vehicles are the main cause of fatalities. Firstly, because they involve an impact with heavier vehicle and the speed of this vehicle, as a rule, is at least twice bigger. High speed and the vehicle weight are two values of an equation causing fatalities. One of the possible solutions to eliminate the accident risk is to reduce the speed limit on roads within localities areas from 50 km/h to 30 km/h, as was done in many European residential areas [4]. 3

Accidents at night are another important issue since 30 % of all victims are cyclists that died during the night trips. The predominant number of accidents in Portugal and other countries occurs in broad daylight. About 80 % of all accidents were recorded in the daytime and 16 % at night. Although most accidents occur in good light conditions, those that occur in low light conditions have more serious consequences. The low light roads are an extreme danger to vulnerable road users during the night. According to the study of Kenneth D. Cross and Gary Fisher, the light device use in bicycle may prevent night-time accidents by 80 %. The distribution of accidents according light conditions in the period 2010-2014 is shown at Figure 2. Figure 2: Distribution of accidents according light conditions during 2010-2014 During night trips it is recommended to use reflective vest and helmet with reflective elements (ribbons, stickers). The next step is to equip vehicle with lighting. MSB is equipped with the luminous LED matrix, size 8 per 8, to signal presence of the vehicle on a road. To conclude observation of accident statistics, it is clear that the side collisions, rear-end collisions and night accidents are the indicators with greater contribution to the number of deaths and serious injuries. Therefore, it is important to study and observe motorists behaviour during overtaking maneuvers and record the distances between bicycle and other motor vehicles. 3 Materials and methods There are several studies about the influence of various factors on the safety distance between the cyclist and the motor vehicle. Ian Walker (2006) found that drivers tend to pass significantly closer to the bicyclist when he/she uses the helmet. Also author discovered that the most experienced drivers of larger and heavier vehicles tend to get closer to the cyclist when making the manoeuvre. In 2010 Jeremy R. Chapman and other authors [5] created a security system for bicycle (laptop + ultrasonic sensor + 2 cameras + GPS tracker) to collect detailed information about the overtaking cases. This study was conducted in the area around Madison (Wisconsin, USA) and it found out that drivers were far more likely to give bicyclists more space than required risking a center line violation, even when 4

conditions were not safe to do so. Ian Walker, this time in 2014, equipped the bicycle with an ultrasonic sensor in order to create a database with lateral distances during overtaking manoeuvre [6]. These authors investigated the influence of helmet use and various equipment (7 different vests) on an average lateral distance between the motor vehicle and the cyclist. The only substantial change in drivers behaviour was seen in response to a high-visibility vest which is associated with a police and suggested the rider was video-recording the journey. The group of investigators analysed lateral clearance between motor vehicle and bicycle of around 3000 overtaking manoeuvres on two-lane rural roads in Spain [7]. Two ultrasonic sensors were used in order to find out lateral distance and the velocity of motor vehicle. A high definition rear camera was applied to observe the overtaking vehicle approach. It was shown how a higher lateral separation, higher speeds and the presence of heavy vehicles influenced the perceived risk, also an aerodynamics force was studied. Dr. Madsen found that the incidence rate is 19 % lower for cyclists with permanent running lights mounted [8]. All described studies served as source of inspiration and motivation to create the security module prototype for bicycles. One of the key aims is to make a discrete device, minimizing a probability of that module being seen by other drivers. Similar to the study of Walker et al., 2014, the core of the prototype is the micro-controller board Arduino UNO. As a study target, we chose the city of Lisbon and its zones located within localities and N10 national road, where the maximum running speed by law is 90 km/h. MSB is a security device which records the moments of potential danger during a move on the public road. Apart from the main function, which is the recording of a data about the lateral and rear distances, the device allows signal manoeuvres and increases the conspicuity of the cyclist on the road. The system consists of the Arduino, ultrasonic sensors, LED matrix and other electronic components: light sensor, Real Time Clock (RTC) module, card reader, buzzer and two mechanical buttons. When Arduino is connected to a power source, for example an alkaline 9 volt battery, the sensors start a recording and then the information on the distances is transferred to a data card. At the table below all inputs and outputs of the system are presented. Low-cost ultrasonic ranging module HC-SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm. The module includes ultrasonic transmitters, receiver and control circuit. The investigation of Japanese author Yoshiaki Taniguchi [9], who installed the HC-SR04 sensor on bicycle, showed that the system (Arduino UNO + HC-SR04) can detect obstacles on the surface of the road ahead the bicycle at a distance of 223cm. Thus, it was concluded that the ultrasonic sensor HC-SR04 is a good option for the security module. 5

Table 1: Inputs and Outputs of the MSB Input Output Power: alkaline or rechargeable battery type 9V Light: light sensor receives information about surrounding brightness Distance: registered by two ultrasonic sensors Turning input: user selects left or right turn In the case of critical distance (1,5m): LED matrix array and red LED lamp turns on In the case of low ambient lighting: blinking light LED matrix During manoeuvres: blinking light LED array with signal concerning the required manoeuvre Critical distance: the buzzer is activated Data: data record on the micro SD card Data: LED lamp turned on continuously in the case of SD card reading error The final cost was determined by two different ways: if the user will acquire all necessary stuff in Lisbon in a commercial electro-technical products stores, the total cost is around 70 Euro; if the user will acquire all necessary elements to build MSB through on-line stores, the final cost is approximately would be 25 Euro. After writing programming code and testing all devices one by one and the system as general unit, the next step was to create layouts and solder all electric modules in order to make the first prototype. All layouts of the components and the final product mounted on the bicycle can be seen at Figure 3. (a) Layout of MSB (b) Instrumented bicycle Figure 3: Layout of the first prototype and Instrumented bicycle. After the construction phase, it is very important to ensure correct operation of all components and of the prototype in general. The first prototype tests are conducted with an intention to find hardware 6

defects or programming code errors before starting complex studies. GoPro action camera was added to complete the tests with high definition video record for further analysis of the type of vehicle and overtaking manoeuvre. Following tests were performed to collect quantitative and qualitative data: A trip of about 23 km on the N10 national road, where at the first half of the route the cyclist used the helmet and at the second half drove without safety equipment; Two trips within localities in the residential area of the Park of Nations, where most of the data were collected at Avenida D. João II, the main street where high flow of cyclists is observed every day and sometimes the road is used as part of the route of several cycling competitions. During the trip it was possible to vary the position on the carriageway, so results were registered depending on various positions; One trip within localities between 9 PM and 10 PM was performed to check out the situation at night. During this night trip both ultrasonic sensors were tested. 4 Results 300 overtaking manoeuvres were recorded over the testing in total. The data distribution during the first trip without helmet and during the second with helmet on N10 national road can be seen at Figure 4. It should be remembered, that the achieved set of data is relatively small to draw conclusions about the situation on the road. However, comparing data from the two pathways we observe the difference in the average distance. The average distance without the helmet is 130 cm, when the recorded distance on the same road with the helmet is 149 cm. The driver was situated near the road shoulder almost all the way. These values are compared with the 1,5 m lateral separation standard, showing that it have not provided enough safety at locations with higher mean overtaking speeds. (a) Distribution of records without helmet (b) Distribution of records with helmet Figure 4: Distribution of the points on N10 national road. 7

During the move within localities, assuming that the width of the traffic lane is L, the cycler conducted two tests taking the the position L/3 and L/2 to see which of the two physical locations is more safe. All data can be seen in Table 2. Table 2: MSB records Number of records Percentage Distance [cm] [0;100[ [100;150[ [150;200[ [200;400[ < 150 150 N10 without helmet 29 59 24 16 69% 31% N10 with helmet 48 23 34 42 48% 52% Position L/3 165 28 83 55 58% 42% Position L/2 13 19 19 43 34% 66% Lateral clearance at night 312 72 49 40 81% 19% Rear clearance at night 0 47 33 105 25% 75% A disadvantage of performing tests in the localities is the large amount of light signals, what means recording data on lateral distance when both vehicles are stationeries. The data taken in this way is useless to study overtaking manoeuvres. In Portugal, as well as in many other countries, the minimum safe distance is 1.5 m between cyclist and motor vehicle [10]. The data obtained show that the safest position for circulation is L/2, where more than half of the records corresponding to a distance greater than 150 cm. However, most of these standards are not the result of any scientific research. They do not rely on any scientific evidence to justify the proposed distance. 5 Conclusion Despite the fact that the principal aim of this project is a development of a security module for bicycle, several tests were performed to prove correct functionality and to study how motor vehicles overtake bicycles on national road N10 and some areas within localities. MBS is a security device that can be mounted on any kind of bicycles and through two ultrasonic sensors record the distance between two vehicles. The main idea was to create a low-cost system that can be build by any student or researcher in the world with some programming and electrical circuit knowledge. The total cost of the prototype was around 70 Euro, of which 25 Euro is a price of a open-source electronics platform Arduino UNO. Also, this research shows that the side and rear impact are two most frequent types of accidents in Portugal, both contribute to approximately 50 % of accidents every year. The reason why author performed all tests in order to record and later analyse data on lateral distance. Due to the long time of construction of the security module and on the other hand limited time available for the tests, the author obtained an insignificant sample of data to draw conclusions about the safety of bicycles in the traffic lane. 8

However, regarding the results of conducted tests, the motor vehicle drivers left greater side distance when the cyclist pedaled the N10 national road with a helmet. In the case without a helmet, only 31 % of motor vehicles effected the overtaking manoeuvre standing at a distance greater than 1.5 meters. L/2 position, right in the middle of the traffic lane corresponds to the safest location for bicycle when it runs on a road with two lanes in each direction. At night the situation is worrying, at 81 % of cases motorized vehicles passed leaving a lateral distance less than 1.5 meters. At night the cyclist travelled only using the LED array as the illumination device. To confirm the operational ability of the developed product, it was used for several tests and successfully registered all the situations of a potential danger. References [1] ERSO - European Road Safety Observatory, Traffic Safety Basic Facts 2015 - Cyclists, 2015, brussels, Belgium. [2] ANSR, Sinistralidade Rodoviária - Relatório Anual 2014, 2015, lisbon, Portugal. [3] T. Lajunen, T. Özkan, and B. E. Porter, Bicycle safety, Transportation Research Part F: Traffic Psychology and Behaviour, vol. 41, Part B, pp. 179 181, 2013. [4] F. P. Vaz, J. M. Dias, and P. Francisco, Sinistralidade com velocípedes: um problema emergente, 2013, 7 o Congresso Rodoviario Português, 10-12 Abril 2013. [5] J. Chapman and D. Noyce, Observations of driver behavior during overtaking of bicycles on rural roads, Transportation Research Record: Journal of the Transportation Research Board, no. 2321, pp. 38 45, 2012. [6] I. Walker, I. Garrard, and F. Jowitt, The influence of a bicycle commuter s appearance on drivers overtaking proximities: an on-road test of bicyclist stereotypes, high-visibility clothing and safety aids in the united kingdom, Accident Analysis & Prevention, vol. 64, pp. 69 77, 2014. [7] C. Llorca, A. Angel-Domenech, F. Agustin-Gomez, and A. Garcia, Motor vehicles overtaking cyclists on two-lane rural roads: Analysis on speed and lateral clearance, Safety Science, 2015. [8] J. C. O. Madsen, T. Andersen, and H. Lahrmann, Safety effects of permanent running lights for bicycles: A controlled experiment, Accident Analysis & Prevention, vol. 50, pp. 820 829, 2013. [9] Y. Taniguchi, K. Nishii, and H. Hisamatsu, Evaluation of a bicycle-mounted ultrasonic distance sensor for monitoring obstacles and holes on road. International Journal of Simulation Systems, Science & Technology, vol. 16, no. 6, 2015. 9

[10] ANSR, 13 a alteração ao Código da Estrada pela Lei n. o 72/2013 de 3 de setembro, 2013, lisboa, Portugal. [Online]. Available: http://www.invicta.pt/pdf/legislacao/codigo%20da%20estrada% 202014.pdf 10