Safety and assistance systems from Daimler Buses once again set the standard for buses

• Active Brake Assist 6 emergency braking system with multi-lane monitoring
• Preventive Brake Assist 2 for city buses
• Sideguard Assist 2 with function extension on the driver's side
• New: Frontguard Assist monitors traffic area in front of the vehicle
• Active Drive Assist 2 provides even better support for the semi-automated driving function
• New: Traffic Sign Assist
• Attention Assist and TPM: from special equipment to series production
• New: optional MirrorCam instead of outside mirrors

Current safety and assistance systems in Mercedes-Benz and Setra buses not only meet the requirements of the GSR, some functions go even beyond the required level or already meet the requirements for 2026 today.

Active Brake Assist 6 emergency braking system with multi-lane monitoring

Active Brake Assist 6 (ABA 6) is a good example of the overfulfillment of the GSR. Using a combination of short- and long-range radar sensors and a camera, the latest Emergency Brake Assist from Daimler Buses can now perform an automated maximum full-stop braking at speeds of up to 60 km/h – the ABA 5 was already capable of 50 km/h – and bring the vehicle to a standstill in front of people in front of the vehicle, oncoming road users or road users driving in the lane. The extended reaction to pedestrians and cyclists is already a preview of the new legislation for emergency braking systems for heavy commercial vehicles, which will only become mandatory at a later date.

At all speeds, the system can react to vehicles in front of the bus with maximum full-stop braking. Under optimal conditions, an accident at speeds of up to around 90 km/h can be prevented. The warning cascade in the event of an impending accident comprises a visual and haptic warning. If the driver fails to react, first partial braking and then emergency braking follows. A further added value of ABA 6 is multi-lane monitoring at distances of up to 250 meters for even better hazard detection. This enables the system to react to critical situations and moving or stationary objects – including, for example, in standard highway cornering situations. At the same time, radar technology generally ensures high system availability even in poor visibility.

Preventive Brake Assist 2 for city buses

An unexpected emergency braking maneuver by a city bus that encounters an obstacle could pose a risk of injury to passengers on board. This is why Daimler Buses uses Preventive Brake Assist in its low-floor buses of the Mercedes-Benz Citaro, eCitaro and Conecto model series as well as in the Setra MultiClass 500 LE for urban and intercity transport – the world's first specialized active brake assistant for regular service buses. It warns of stationary obstacles as well as pedestrians and cyclists and can initiate partial braking if the driver does not react. Like Active Brake Assist 6, the new, second generation of this assistance system works with a combination of short and long-range radar sensors as well as a camera and is thus able to react to stationary and moving objects, including pedestrians and cyclists. The system can process multiple objects at the same time. Within the system limits, objects located outside the roadway are also detected even better and false warnings are minimized.

Preventive Brake Assist 2 warns the driver of a collision with stationary or moving objects both visually by means of a red warning light on the central display and also acoustically. At the same time, it also automatically initiates a braking maneuver with partial braking. Similar to emergency braking of ABA 6, it is held until either the driver intervenes, or the situation is no longer critical or the bus comes to a standstill. However, the warning cascade and brake application are precisely designed for use in scheduled services and therefore for the safety of standing passengers. Preventive Brake Assist 2 is another milestone, especially for the protection of vulnerable road users in urban and intercity traffic.

Active Sideguard Assist 2 with extended functionality on the driver’s side

The second-generation Sideguard Assist also demonstrates the extent to which equipping the vehicles with six sensors and the associated increased viewing angle increases road safety. Thanks to the new sensor concept, the new Sideguard Assist reacts and warns even more precisely in the event of a risk of collision with pedestrians and cyclists. It is now also used on the driver’s side. This also makes turning left even safer. Up to a speed of 30 km/h, the lateral monitoring zone on the front passenger side has a width of 4.25 meters (previously 3.75 meters) and extends 30 meters behind and seven meters in front of the vehicle. At speeds above 30 km/h, Sideguard Assist 2 also has the function of a lane change assistant. Up to the maximum permissible speed, it informs the driver of an object on the driver’s and passenger’s side. The system generates a visual and haptic warning in critical lane change situations. Sideguard Assist 2 thus supports lane changes, for example when overtaking a cyclist or when changing lanes/overtaking on multi-lane roads.

New: Frontguard Assist monitors traffic area in front of the vehicle

In the hectic pace of everyday working life, it is easy for drivers to start the engine or pull away at a traffic light with their eyes already on the road ahead. This can have serious consequences if there are unprotected road users such as pedestrians or cyclists directly in front of the bus. The new Frontguard Assist from Daimler Buses can be a helpful feature to avert accidents in such situations. If the system detects stationary or moving objects in front of the vehicle, it can support drivers at speeds of up to 15 km/h by sending hazard alerts via the two-stage warning system. The assistance system monitors the blind spot in front of the vehicle over a distance of 0.8 meters up to approximately four meters across the full width of the vehicle. Sideguard Assist 2 and Frontguard Assist combine to create a complete warning system that warns of obstacles and people at the sides and in front of the bus. Combined with the standard reversing camera or, even more so, the optional 360° camera system, the driver is provided with a comprehensive warning system all around the bus.

Active Drive Assist 2 supports the driving function for semi-automated driving

Active Drive Assist 2 (ADA 2) now offers the driver even greater assistance in maintaining distance and staying in the lane. The system is also equipped with an emergency stop function. In the ADA 2, all assistance systems work hand in hand and support each other: For example, Active Drive Assist 2 acts according to the specifications of Predictive Powertrain Control (PPC) to ensure the most economical driving style possible. For longitudinal and lateral guidance of the vehicle, the system uses functional extensions based on the proven Adaptive Cruise Control (ART) and Lane Assist. ADA 2 also uses the advanced radar and camera technology of Active Brake Assist 6 (ABA 6) to detect traffic ahead. An emergency stop function is also implemented. This brings the vehicle to a standstill by means of moderate, automated braking if the driver no longer reacts.

An essential component of Active Drive Assist 2 is the active lateral guidance within the lane by Active Steering Assist with an electric motor to support the hydraulic steering and the connection with the longitudinal guidance of the Adaptive Cruise Control (accelerate/brake/maintain distance) by merging radar and camera information. With the active steering assistant, Active Drive Assist 2, also keeps the bus within the lane when ART is activated by means of continuous steering interventions at a target position that can be set by the driver. The driver can choose between three settings: Either the bus drives exactly in the middle of the lane or, depending on the width of the lane, slightly offset to the left or right by ten to 20 centimeters. The system thus considerably reduces the driver’s workload by relieving him of a large part of the continuous minor steering corrections for lane keeping. Like the ART, the active lateral guidance by the active Steering Assist is active over the entire speed range of the touring coach from 0 to 100 km/h. Prerequisites for the system: The lane must be clearly marked by lines on both sides.

A green steering wheel symbol in the central display signals the driver that the active steering assistant is assisting with lateral guidance of the vehicle. If the driver does not wish to use the comfort assistance function due to the current traffic situation, he can deactivate it. Even when Active Drive Assist 2 is deactivated, the tried-and-tested Adaptive Cruise Control continues to take over the longitudinal guidance of the vehicle, in conjunction with the anticipatory Predictive Powertrain Control (PPC) cruise control system. The adaptive cruise control slows down the bus before it gets too close to the vehicle in front and then accelerates it back up to the speed set by the driver. If necessary, the adaptive cruise control even slows the bus down to a standstill with partial braking.

Active Drive Assist 2 was developed for driving on highways and highway-like roads, which is why a minimum lane width is required. The system becomes passive when system limits are reached, such as unclear lane markings, lanes that are too narrow or curve radii that are too tight. This is accompanied by a warning to the driver, signaled by a corresponding display in the cockpit.

Despite the assistance provided by Active Drive Assist 2, the driver always remains responsible. If the driver takes their hands off the steering wheel, a warning cascade is triggered in accordance with legal requirements (hands-off warning cascade). After 15 seconds, the driver assistance system warns with a yellow signal followed by a red display on the instrument panel, and then with acoustic warnings at increasingly shorter intervals until the continuous warning tone is sounded. If 60 seconds have elapsed since the beginning of the hands-off warning cascade without the driver's hands returning to the steering wheel, the Emergency Stop function is activated. This initiates a speed reduction by releasing the gas pedal for one second. This is followed by speed reduction. The Emergency Stop function now takes over control of the vehicle within the system limits in order to keep it in its lane. The headlamp and hazard warning light system is activated 5 seconds before the end of the hands-off warning cascade to warn following traffic and the vehicle is gradually slowed down to a standstill. When the vehicle is stationary, the electric parking brake is activated and the hazard warning light system continues to flash. During the intervention of the Emergency Stop function, the driver is continuously informed by an acoustic continuous beep and a visual warning in the display about the emergency stop and the possibility of override and can cancel the process by kickdown.

New: Traffic Sign Assist

Another new feature is the intelligent speed limit assistant Traffic Sign Assist. It compares the current speed of the bus with the permissible vehicle speed and issues a warning if the permitted speed is exceeded. It works despite different signage throughout Europe. Traffic Sign Assist can thus reduce the risk of accidents due to excessive speed and inattentiveness. It also reduces the risk of fines due to excessive speed.

Attention Assist and TPM: from special equipment to series production

The previously optional tire pressure monitoring system TPM (Tire Pressure Monitoring) also becomes part of the standard equipment. TPM prevents tire damage by indicating a possible pressure loss. In addition, correct tire pressure reduces both wear and fuel consumption.

Attention Assist (AtAs) and an interface for the use of alcohol testers in the driver cockpit are now also in series production. The same applies to the previously optional reversing camera. Depending on the model series, its image is transmitted to an existing monitor in the cockpit or to an additional seven-inch monitor. As an alternative to the reversing camera, companies can also choose the 360° camera system (articulated buses: 270° camera system).

New: Optional MirrorCam instead of outside mirrors

All bus/touring coach model series from Mercedes-Benz and Setra, whether urban, intercity or touring coaches, are optionally available with cameras instead of the previously installed outside mirrors. This eye-catching novelty not only changes the appearance of the vehicles to a body without visible detachable parts – it also affects function, safety and profitability.

The advantages are obvious: Extended field of vision for the driver through the windows, significantly better visibility to the rear in the dark thanks to residual light enhancement. The small surface of the camera lens is less susceptible to dirt and better protected against the effects of the weather thanks to its installation in the camera wing. Compared to conventional mirrors, MirrorCam barely or only slightly protrudes beyond the vehicle edges. This means easier maneuvering and less damage. Ultimately, the front end surface of the bus/touring coach is reduced, causing less turbulence. This has a positive effect on fuel consumption.

This is how MirrorCam works: The images from the cameras are transmitted to 15-inch monitors mounted on the inside of the A-pillars. Exceptions are the low-floor buses of the Citaro range and the MultiClass LE: As a result of the design of vehicles with glazed driver’s cabs and inward-swinging doors, the monitors on the door side are arranged in approximately the center of the vehicle. Superimposed lines signal the end of the vehicle and help the driver to estimate the speed of approaching vehicles, as well as when cutting in at the end of an overtaking maneuver. They are activated by engaging reverse gear or by operating the turn signal lamps. An additional camera and a second monitor in seven-inch format ensure a view of the front right corner of the vehicle.

The camera is heated. Photodiodes in the monitors detect the incident light and adjust the brightness of the monitors individually. In addition, the driver can configure a basic setting. Sideguard Assist warning displays can be shown on the monitors if desired.