Blind-Spot & Vulnerable Road User Protection

---

Most HGV-related cyclist and pedestrian fatalities in the UK happen in two specific zones: the nearside blind zone during left turns, and the area immediately ahead of the vehicle at moving-off. Standard mirrors don’t cover either zone adequately on a high-cab HGV. The Direct Vision Standard data showed that addressing these two zones reduced HGV-related serious injuries and fatalities in London by approximately 50% within five years of enforcement. Blind-spot and VRU protection isn’t an optional safety upgrade — it’s the engineering control that the regulatory data identifies as the most consequential single intervention.

Backwatch supplies the camera, sensor, and audible warning components that address both zones — UNECE Regulation 151-compliant BSIS sensors for the nearside, UNECE Regulation 159-compliant MOIS for the front, side cameras for direct visibility replacement, and external audible warnings to alert VRUs outside the vehicle.

The two critical zones

Blind-spot and VRU protection on UK fleet vehicles addresses two specific risk zones:

• Nearside blind zone (cyclists at left turns). A cyclist alongside a UK HGV at a left-turn junction is in the most consistently fatal collision pattern in the data. The driver looking in mirrors and through the cab window cannot reliably see a cyclist at road level on the kerb side. CMS camera + BSIS sensor + external left-turn audible warning together address this — visual coverage in the cab, automated detection, and alerting the cyclist outside the vehicle.
• Front blind zone at moving-off (pedestrians). A pedestrian standing immediately in front of an HGV cab is below the driver’s sightline and isn’t visible in standard mirrors. When the vehicle moves off, the pedestrian can be struck before the driver knows they were there. MOIS — AI-based pedestrian detection covering the immediate forward zone — alerts the driver before the vehicle moves.

Featured products in our VRU protection range

Specification by zone

Risk zone	Detection	Visual coverage	Alert (in-cab)	Alert (external)
Nearside blind zone	BWBSIS Sensor (UNECE R151)	BW690, CW406, MS311 side camera	Audible/visual on left indicator + below 30km/h	LTAbgt left-turn alarm
Front blind zone	BWMOIS (UNECE R159), BWFR77GHZ, BWAI	BW686 forward camera	AI pedestrian alert before move-off	—
Combined nearside + front	BWBSISMOISCOM single unit	BW690 + BW686	Both standards apply	LTAbgt + MOIS unit

How the components work together

Nearside protection — three-component system

Standalone BSIS sensors, side cameras, and left-turn alarms each address part of the nearside risk. The integrated system combines all three:

• BWBSIS Sensor detects a person in the nearside zone using radar — works regardless of driver attention, light conditions, or weather. Generates in-cab audible/visual alert during left turns and below 30 km/h.
• BW690 Side Camera provides the in-cab visual feed of the kerbside zone — fitted alongside Class V/VI mirrors for DVS PSS purposes. Indicator-activated to direct the driver’s attention to the nearside view at the moment a left turn is being executed.
• LTAbgt Left Turn Alarm is the external audible warning — alerts the cyclist or pedestrian outside the vehicle that the HGV is about to turn left. The third party can take action; the warning doesn’t depend on driver attention.

All three components activate on left indicator, so they work as a single coordinated alert system rather than independently.

Front protection — MOIS

MOIS uses AI-based detection to identify pedestrians in the area immediately ahead of the vehicle at ground level — the zone the driver cannot see from the high cab position. The system activates when the vehicle is stationary (just before moving off) and alerts the driver if a pedestrian is detected. This addresses a specific incident pattern that cameras alone don’t fully address: the driver may not be looking at the front camera at the moment they begin to move.

Three MOIS options:

• BWMOIS — dedicated camera-AI MOIS unit (standard fitment)
• BWFR77GHZ — 77GHz radar variant for vehicles with extended bonnet profiles or where camera mounting space is restricted
• BWAI — AI camera variant for fleets standardising on AI processing across PSS and FORS programmes

For installations with limited mounting space, the BWBSISMOISCOM combines BSIS and MOIS functions in a single unit — useful for retrofitting older vehicles where the front and nearside positions can’t accommodate two separate units.

By compliance framework

Framework	Nearside requirement	Front requirement
DVS PSS	CMS camera + BSIS (R151)	MOIS (R159)
FORS Silver	Side and rear cameras + BSIS-type (rigids over 7.5T)	Optional
FORS Gold	Same as Silver	Optional
CLOCS	References FORS Silver	Optional
WISH WASTE-04	Cameras and/or sensors recommended	Recommended

By vehicle type

• Construction tippers and grab lorries: Full nearside system (camera + BSIS + left-turn alarm) for FORS Silver / CLOCS / DVS PSS. MOIS additionally for London routes. The grab arm zone is not covered by standard nearside protection — additional camera coverage recommended for FORS Gold.
• Refuse collection vehicles: Nearside system mandatory (FORS Silver + WISH WASTE-04). MOIS for DVS PSS London routes. Bin lift zone has separate LOLER requirements.
• Articulated logistics: Nearside system + FORS V7 (January 2025) sensor positioning to prevent false alerts from trailer articulation.
• Coaches and PSV: Nearside system for over-12T coaches (DVS PSS). MOIS particularly relevant for tourist-stop and hotel drop-off pedestrian risk.
• Quarry and off-road industrial: Different framework — engineering controls under MHSWR rather than DVS PSS. Side and rear sensors with extended detection range; AI-based detection for high-risk operations.
• Council fleets: Standard nearside system + MOIS for refuse and large maintenance vehicles. Additional cyclist-zone coverage recommended where the council has high-volume cycling routes.

Why the integrated system matters

Each component on its own addresses part of the VRU risk, but the combined system delivers protection that no single component can:

• BSIS without camera alerts the driver but doesn’t provide visual confirmation of what was detected — drivers learn to question the alert and may dismiss genuine warnings.
• Camera without BSIS requires the driver to look at the monitor at exactly the right moment — the BSIS sensor automates the detection regardless of driver attention.
• External warning without sensors alerts road users but doesn’t tell the driver there’s anything to alert about — the cyclist can move clear, but if the driver doesn’t know there’s a cyclist, they don’t moderate their turn.
• MOIS without nearside protection covers front-zone pedestrians but leaves the larger nearside cyclist risk unaddressed.

The integrated system addresses the failure mode of each individual component by ensuring the others are also active.

Installation and support

• On-site fitting across England and Wales — typical 4–5 hours per vehicle for full nearside + front VRU protection
• Weekend fitting available — at no extra cost
• 2-year product warranty on cameras, sensors, and audible warnings
• UNECE certification — BWBSIS (R151), BWMOIS (R159), with installation certificates for TfL submission
• FORS Version 7 (January 2025) sensor positioning applied to articulated installations
• Per-vehicle calibration — sensor exclusion zones configured for each vehicle’s body profile

Frequently asked questions

Is BSIS the same as a parking sensor?

No. A parking sensor is typically ultrasonic, short-range (under 2m), and designed for low-speed parking manoeuvres. A BSIS (Blind Spot Information System) sensor is radar-based, programmable to longer ranges (5m+), and designed for the specific UK HGV nearside cyclist risk during left turns at junction speeds. UNECE Regulation 151 specifies the performance requirements: detection zone, response time, false-alert rate, and indicator-activation logic. Backwatch’s BWBSIS is R151-compliant; standard parking sensors are not.

Why does MOIS specifically use AI rather than radar?

MOIS targets a specific pattern: a pedestrian standing in front of a stationary vehicle at moving-off. The detection requirement is to identify a person (not just any object) in the immediate forward zone. Radar can detect objects but cannot reliably distinguish a pedestrian from a bollard, a road sign, or a parked vehicle. AI-based image detection trained on pedestrian recognition can make this distinction — the alert is meaningful (someone is at risk) rather than false-positive prone (object detected, no action needed). UNECE Regulation 159 specifies AI-based pedestrian detection for this reason.

Do I need both BSIS and a CMS camera, or is one enough?

Both are required for DVS PSS. The CMS camera provides the visual feed (the Class V/VI mirrors remain fitted); the BSIS sensor provides automated detection. They serve different functions and complement rather than replace each other. FORS Silver requires side and rear cameras (rigid vehicles over 7.5 tonnes) plus a BSIS-type sensor. The reason is that each addresses a different failure mode: the camera fails when the driver isn’t looking; the sensor fails when the alert is dismissed without visual confirmation. Together they’re robust; individually each has gaps.

What’s the difference between MOIS and a front parking sensor?

MOIS uses AI detection to specifically identify pedestrians; a front parking sensor detects any object in close range. MOIS activates before the vehicle moves off; a parking sensor activates during low-speed manoeuvring. For DVS PSS compliance, MOIS-specific equipment is required — UNECE Regulation 159. Front parking sensors don’t satisfy the regulation regardless of how well they detect generic obstacles. The functional difference: MOIS tells the driver “there’s a person in front of the vehicle, don’t move yet”; a parking sensor tells the driver “there’s something close, slow down”.

Can existing nearside cameras and sensors be upgraded to FORS V7 specification?

For most installations, yes. Cameras are typically not affected by V7 changes; the V7 update specifically targets sensor positioning on articulated configurations. Sensors installed before January 2025 on articulated vehicles should be reviewed against V7 — the position may need to be adjusted to prevent false alerts during trailer articulation. Backwatch can audit existing installations and provide an upgrade plan; the recalibration is typically faster and cheaper than full sensor replacement.

How does the LTAbgt left-turn alarm avoid being a noise nuisance?

The LTAbgt is volume-configurable and indicator-activated — it only sounds during the left turn itself, not continuously during normal driving. For fleets concerned about community impact (refuse collection in residential areas, urban delivery, council operations), the volume can be set to the minimum effective level. The trade-off is the volume must be loud enough that a cyclist with traffic noise around them can hear it — this calibration is part of installation and varies by operating environment.

What happens to the system at higher speeds where BSIS doesn’t activate?

BSIS is designed for the junction-speed risk: cyclists alongside a turning HGV in urban traffic. Above 30 km/h, the activation logic disables the alert because the risk profile changes (cyclists rarely match HGV speed on motorways or A-roads). The CMS camera continues to provide visual coverage at all speeds — the camera doesn’t switch off, only the sensor’s audible alert does. For higher-speed risk (overtaking cyclists on rural roads), the camera and the driver’s awareness are the controls, not the BSIS alert.