MDVR for Buses: Channels, Storage and When You Need One

What an MDVR is, how 4-channel and 8-channel mobile DVRs differ, SD card vs hard disk storage, and how to decide between an MDVR and an AI dashcam for a bus.

Short answer: an MDVR (mobile digital video recorder) is a recorder fitted inside a bus that stores video from several cameras at once, usually four or eight. Choose one when a bus needs many cameras recording all day. For driver safety with one or two extra views, an AI dashcam is simpler and gives real-time alerts that a plain MDVR does not.

What is an MDVR?

It is a ruggedised recorder built for vehicles. Cameras around the bus are cabled to it. It records all of them together onto an SD card, hard disk or SSD, stamps the video with time and often GPS location, and on connected models sends video over 4G. It is usually installed out of sight, in a locked compartment. See the MDVR glossary entry.

What does “channels” mean?

One channel is one camera input.

• 4-channel: typically front, driver, gangway and door, or front, gangway and two sides.
• 8-channel: adds both doors, both sides, rear and a second cabin view. Used on long city buses and where full coverage is specified.

Count the views you need before you choose. Unused channels cost little. Too few cannot be fixed without replacing the recorder.

SD card or hard disk?

• SD cards have no moving parts, which suits vibration, but hold less. Fine for a few cameras or shorter retention.
• Hard disks hold far more, for many cameras over many days, but need anti-vibration mounting.
• SSDs combine capacity with no moving parts, at a higher price.

How many days of video will it keep?

That depends on the number of cameras, the resolution and frame rate, how many hours the bus runs each day and the storage size. The recorder overwrites the oldest video when full. Ask the supplier to work out retention for your exact configuration, and write the figure into the order.

What should you check when buying an MDVR?

1. Channels, with one or two spare.
2. Resolution per channel when all channels record together.
3. Storage type and capacity, and the retention it gives you.
4. Power input range that covers 24 V bus electrics, with clean shutdown after ignition off.
5. 4G and GPS, if you want remote viewing and location on the video.
6. Remote access: can footage be viewed and downloaded from the office?
7. A lockable enclosure, so storage cannot be removed casually.
8. Cameras rated for the position: sealed for outside, infrared for a dark cabin.
9. Service on your routes.

MDVR or AI dashcam?

• Choose an AI dashcam when the priority is the driver and the road: collision, lane and drowsiness alerts, with up to two extra cameras for a gangway or blind spots.
• Choose an MDVR when the priority is coverage: many cameras, long retention, full cabin and door recording.
• Use both where a contract asks for full surveillance and driver alerts.

See AI dashcam vs MDVR and the bus CCTV guide.

What is the most common mistake?

Buying a recorder with no remote access. The video then exists only on a disk in a compartment on a bus that may be in another state. When something happens, someone has to travel to fetch it, and by then the recording may have been overwritten.

AirFi supplies AI dashcams with add-on cameras and advises on larger camera systems for buses. Talk to our team about the right setup.

Frequently asked questions

Related solutions

• AI dashcam for buses and commercial vehicles