  Vulnerable Road User (VRU) safety has been an important issue throughout the
years as corresponding fatality numbers in traffic have been increasing each
year. With the developments in connected vehicle technology, there are new and
easier ways of implementing Vehicle to Everything (V2X) communication which can
be utilized to provide safety and early warning benefits for VRUs. Mobile
phones are one important point of interest with their sensors being increased
in quantity and quality and improved in terms of accuracy. Bluetooth and
extended Bluetooth technology in mobile phones has enhanced support to carry
larger chunks of information to longer distances. The work we discuss in this
paper is related to a mobile application that utilizes the mobile phone sensors
and Bluetooth communication to implement Personal Safety Message (PSM)
broadcast using the SAE J2735 standard to create a Pedestrian to Vehicle (P2V)
based safety warning structure. This implementation allows the drivers to
receive a warning on their mobile phones and be more careful about the
pedestrian intending to cross the street. As a result, the driver has much more
time to safely slow down and stop at the intersection. Most importantly, thanks
to the wireless nature of Bluetooth connection and long-range mode in Bluetooth
5.0, most dangerous cases such as reduced visibility or No-Line-of-Sight (NLOS)
conditions can be remedied.
