The Integrated Smart Advanced Warning Unit (I-SAW-U) is an Advanced driver assistance system (ADAS) designed to alert Bus Captains of objects such as other vehicles, cyclists and pedestrians approaching and within their blind spots while on the roads. The system is jointly developed by the Land Transport Authority (LTA) and ST Engineering Land Systems (Formerly known as ST Kinetics).
The I-SAW-U system comprises a set of four cameras sensors and two ultrasonic sensors installed around the bus. When a vehicle, cyclist or pedestrian approaches the bus, the camera sensors detect them as obstacles. An alarm will sound and the location of the obstacle will be displayed visually on a new screen installed at the Driver’s Cockpit. I-SAW-U also provides alerts if the bus is travelling too close to a vehicle in front, if a pedestrian steps in front of the bus, or if the bus captain strays off his lane.
The screen reflects two levels of alerts based on the proximity of the obstacle: an amber alert when the obstacle is 1m away, and a red alert when the obstacle is between 0.5m to 0.8m away from the bus. These thresholds can be redefined in the future. In addition, the two ultrasonic sensors mounted on the roof of the bus are able to detect and warn drivers if they are about to hit an overhead obstacle.
Finally, the I-SAW-U also comes with additional features, such as blinker lights and buzzers mounted outside the bus, which can alert other road users, such as cyclists, if they are riding too close to the buses. These will be activated later during the trial.
An initial six-month trial was conducted in April 2018, with 20 public buses being equipped with the system.
Other Driver Assistance systems
The Mobileye Shield+ Collision Avoidance System is an alternative driver assistance system which also monitors the blind spots of the front, side and rear of the bus. As of April 2018, three buses are equipped with the system: SBS6650K (as part of a trial), as well as SG5999Z and SG4003D. Three cameras installed on the bus feed information to three separate indicator displays depending on the proximity of the potential hazard. More information about the system at the dedicated article.
In addition, SG4002G features a Surround View Camera System, which uses four cameras mounted on the bus (front, rear, both left and right sides) to generate a top-down view of the vehicle in real time, with audio alerts if the bus approaches too close to other road objects.
Land Transport Authority (LTA) Trial
On Monday, 16 April 2018, a six month trial of the I-SAW-U system commenced.
5 buses from each of the 4 Public Transport Operators (SBS Transit, SMRT Buses, Tower Transit Singapore & Go-Ahead Singapore) were installed with the I-SAW-U system for Bus Captains to provide feedback during operations. So far, only MAN A22 & MAN A95 buses were observed to be equipped with the system.
The buses installed with the I-SAW-U system are as follows:
|LTA – ST Engineering I-SAW-U Trial|
|Operator||Bus Model||Bus Registration No.|
|SBS Transit||MAN A22||SMB3076Y|
|SBS Transit||MAN A22||SMB3079P|
|SBS Transit||MAN A22||SMB3096P|
|SBS Transit||MAN A22||SMB3097L|
|SBS Transit||MAN A22||SMB3122Y|
|SMRT Buses||MAN A95||SG5740C|
|SMRT Buses||MAN A95||SG5741A|
|SMRT Buses||MAN A95||SG5745P|
|SMRT Buses||MAN A95||SG5747J|
|SMRT Buses||MAN A95||SG5755K|
|Tower Transit||MAN A22||SMB3001M|
|Tower Transit||MAN A22||SMB3002K|
|Tower Transit||MAN A22||SMB3003H|
|Tower Transit||MAN A22||SMB3004E|
|Tower Transit||MAN A22||SMB3005C|
In January 2019, several MAN A95 (Euro 6) as well as MAN A22 (Euro 6) buses have been spotted with the I-SAW-U system installed. It is expected that the I-SAW-U system will be rolled out by ST Engineering to fulfil the collision warning system requirements for its newly-delivered MAN Euro 6 buses.
These buses can be identified by the external side-mounted blinkers and additional cameras at the rear of the bus.