1.AbstractEvery day we are seeing a lot of accidents happening around the world.In 2015 Tamilnadu records the highest percentage of people who met with traffic accident injuries. An effective way for reducing these traffic fatalities is to first develop automatic traffic accident detection system and second is reducing the time when first emergency responders reach that place. Nowadays BMW is manufacturing vehicles with an in-built automatic accident detection and notification system. Even though, this is a better approach and may work fine but this is very much expensive, complex and may not be available for all the vehicles and the maintenance costs are also very high comparatively. Nowadays we can detect traffic accidents using smart-phones and that ability has only recently become possible because of the technological advancements such as different sensors deployed in our smart-phones and their processing power.In our proposed work we use smart-phones for accident detection. The whole system relies on the G-Force value (extracted from smart-phone accelerometer sensor) to detect an accident in the offline mode. To elucidate the fall detection technique, we use the waveform sequence of the tri-axial accelerometer (X, Y&Z Axis) on the smart-phone as the system inputs. The acquired signals are then compared with our threshold G-Force value so that it can fetch the GPS location of the smart phone thereby track the victim.The application consists of two phases , the detection phase which is used to detect an accident and the notification phase which is used to send a detailed information such as accident location longitude and latitude coordinates, an emergency message to the emergency responders (emergency contacts that were set earlier) when an accident happens. This will be useful for the fast response as the person who received those help notification can immediately call the nearby hospital and can request for emergency service. The message(SMS) is generated based on phone tower signal andif the phone is switched off in any case then the last updated location will be sent. Here we use the GSM technology to send the message and the location via SMS. The proposed android application can work good even in low signal strengths and can also run in background.Keywords: Tri-axial Accelerometer Sensor, G-force value, Emergency contacts, Latitude and Longitude Coordinates. 2.Introduction Nowadays the accident rate has been gradually increasing everyday along with the rapid development of a transportation system . The automobile has a great importance in our daily life. We use it to go to our workplace, keep in touch with our friends and family, and deliver our goods. The rate of automobiles has been increasing by 6% every year. But it can also be a disaster to us and even can kill us through accidents. 2017 Traffic accident record shows that 1250 road accidents happen everyday in India 400 people die every day only due to road crashes. In 2016, TamilNadu registered a total of 69,059 accidents, nearly 14 percent of all road accidents in India. Speed is one of the most important and basic risk factors in driving. It not only affects the severity of a crash but also increases the risk of being involved in a crash.So our proposed work can help such victims and reduce the fatality rate.We basically develop an android application for accident detection and notification.Nowadays everyone are using smart-phones because of it’s low cost and high features and also most of the people frequently change their smart-phones when compared with vehicles.The advantage of using smart-phones for detecting accidents is that the technological innovations has been improving day by day with new software’s and hardware’s like sensors,communication interfaces etc helps in performing various tasks and in our proposed work it helps in detection and notification during accidents.In our paper we have implemented an android application that runs from Android 4.0 till the latest Android 7.1.1(Nougat). The accident detection can be done by using various sensors deployed in our smartphone such as triaxial accelerometer and also by using human fall detection technique. This triaxial accelerometer calculates the G-force value in X, Y & Z axis and if the G-force value greater than the threshold value then the emergency message will be sent to our emergency contacts.The coordinates at that particular axis can be fetched using the tower signal from the base-stations.The GSM technology can be employed so that there is no need for any internet connectivity.The already existing work related to this concept is to calculate the G-force value using the 3G/4G internet connections. And this model works only when connected to the internet and another related existing work is in which some wearable sensors which we found as durable as it is not comfortable to everyone to carry the sensors to each and every place and the cost of this method is also much higher due to the usage of many sensors. Our Proposed work has two phases the detection and notification phase the detection phase used to detect the abnormal threshold value and capture the place Co-ordinates ‘ie’ Longitude and latitude points and the notification system use the service providers cellular network signal and sends the GSM precisely it will send SMS to our emergency contacts without the use of any GPRS,3G etc. In our proposed work we have an idea to develop an android application in which we develop a sign up activity and login activity and we create a local database and link the login contacts to the database and if the application is started after the login activity the G-force value is calculated and if any abnormal ratios are identified greater than the fixed threshold value then the message and the coordinates will be sent through SMS and if in any condition the smartphone breaks due to severe accidents the last travelled location of the mobile network captured and sent to the emergency contacts. In the previous works the android application works only when the application is ON and doesn’t work when the application is running in background. In our work we are trying to implement the application even which works in background.