Radio Data System (RDS) 

RDS stands for Radio Data System and is a radio broadcasting corporation service. As well as the audio broadcast programme, information is transmitted in the form of encrypted digital signals which can be analysed by RDS-ready radios. This makes it possible to transmit additional services such as broadcaster name (PSN), radio text (RT) or the labelling of traffic programmes (TP) or traffic disruption (e.g. traffic jams, accidents, road closures via TMC). Transmission of alternative frequencies (AF) in RDS permits adjustment to the frequency of the current broadcast programme with the best reception.  When a signal becomes weaker, the radio switches automatically to an improved broadcast frequency of the same station.
Traffic Announcement (TA) conveys traffic reports at a preset volume, even when other sources (CD, SD or other media) are being played or the radio is switched off. Within a broadcasting network, the system also automatically switches from a station not broadcasting traffic news to the relevant traffic news station (EON, Enhanced Other Network).
The radio station operators are responsible for the accuracy of RDS information. RDS is already in use throughout Europe. However, in other parts of the world (e.g. North America, China), RDS is playing an increasingly important role in conjunction with broadcaster name (PSN) and traffic information (TMC).

Volkswagen on-board computer with focus on the Radio Data System

 Radio Navigation System

The radio navigation system combines navigation with multimedia entertainment.

See also:
Navigation system

Image of the radio navigation system in the on-board computer of a VW Passat

Rain sensor

Volkswagen's rain sensor automatically controls the wipe frequency of the wiper according the intensity of the rain. The sensor at the base of the interior mirror consists of several infrared LEDs and one central photodiode. The light emitted by the LEDs is reflected by the windscreen to the photosensor. The more water droplets are on the windscreen, the less light is received by the sensor. This information is passed on to an electronic control unit that adjusts the wiping frequency of the wiper accordingly. The sensor’s sensitivity can also be adapted using a selector switch.

The rain sensor is designed so that neither minor damage, dirt nor ageing of the windscreen can have a negative impact on its function. The driver can focus all their attention on what's happening on the road without having to change the wiping frequency. This is a major benefit, particularly in the event of sudden obstructions of view, such as when overtaking a lorry on a wet surface.

Image of the rain sensor in the VW Up!’s windscreen

Ramp angle  

The ramp angle describes the transition angle from a horizontal level to a gradient.

Schematic diagram of the ramp angle in a VW Touareg


The range is the distance that can be covered with a fully charged battery without the need to recharge. The actual range depends in practice on the driving style, speed, use of comfort features and auxiliary equipment, ambient temperature, number of passengers, load and terrain.

Illustration of a map of Europe


The RDE test procedure is used alongside WLTP to measure emissions in Europe. RDE stands for Real Driving Emissions. Unlike with NEDC and WLTP, emissions are not measured on the test bed, but in moving traffic. The emissions detected while driving in traffic are known as real emissions.

RDE driving cycle
In RDE measurement, a route mix with random acceleration and braking lasting between 90 and 120 minutes is travelled. The vehicle is equipped with a PEMS (Portable Emissions Measurement System) test box. This device measures exhaust emissions (nitrogen oxides and carbon monoxide) and the associated engine, vehicle and environmental parameters on a predefined route. In combination with GPS data, these help establish a more precise correlation between driving situation and exhaust gas output.  

See also:

A VW Golf driving through a city at dusk, front view

Rear Seat Entertainment (RSE)  

Volkswagen’s exclusive rear seat entertainment system offers rear seat passengers top-level multimedia entertainment. The main components are a flat TFT screen in the headliner or two screens in the front seat head restraints, a DVD player and an additional control unit in the rear centre console. This also has headphone jacks to help avoid disturbing other passengers and an extra video and audio input. An external source can be connected, such as a games console.
DVD sound is output either through headphones or via the radio system speaker. To ensure the driver and passengers can still listen to the radio while a DVD is playing, Rear Seat Entertainment and the radio system can also be operated separately.

Graphic display of Rear Seat Entertainment screen in VW Touareg

Rear Traffic Alert  

The Rear Traffic Alert helps drivers, within the system’s limitations, drive out of a parking space. Sensors in the rear bumper allow the system to monitor the area behind the vehicle and to the side much sooner than the driver. If the vehicle becomes critically close to another vehicle, the driver is informed by a sound. If the driver does not react, in the event of an upcoming collision, the system can reduce or ideally prevent the potential consequences of an accident.
The Rear Traffic Alert is offered in combination with the Blind Spot Sensor or ‘Side Assist’ lane change system.

See also:
Blind Spot Sensor
‘Side Assist’ lane change system