7.2 Vulnerable Road Users & Shared Road Space

Defining Vulnerable Road Users (VRUs) in Urban and Rural Ireland

Commercial bus drivers operate large, heavy vehicles weighing between 12 and 18 tonnes when fully loaded with passengers. In contrast, Vulnerable Road Users (VRUs)—which include pedestrians, pedal cyclists, e-scooter riders, motorcyclists, mobility scooter users, and horse riders—possess little to no physical protection against kinetic impact. In any collision between a Category D vehicle and a VRU, the physical force transferred to the unprotected individual almost invariably results in catastrophic or fatal injuries.

In Ireland's evolving transport landscape, urban initiatives such as BusConnects in Dublin, Cork, Limerick, and Galway have increased the density of shared road infrastructure, quality bus corridors (QBCs), and integrated cycle tracks. Consequently, bus drivers share narrow urban lanes, traffic light junctions, and bus stops with thousands of commuters utilizing active travel and micro-mobility modes daily. Maintaining a high level of hazard perception, empathy, and statutory compliance is paramount to protecting human life on shared roadways.

---

Safe Overtaking Clearances & Micro-Mobility Handling

RSA Safe-Passing Guidance for Cyclists and E-Scooters

RSA guidance tells drivers—especially drivers of large vehicles—to allow at least the following lateral space when overtaking pedal cyclists and e-scooter riders. The figures are safe-passing guidance; the legal duty remains to overtake only when it can be completed without danger:

• Speed Zones Up to 50 km/h: Drivers must allow a minimum lateral passing distance of 1.0 metre between the leftmost point of the bus (including mirrors) and the cyclist or e-scooter rider.
• Speed Zones Exceeding 50 km/h: Drivers must allow a minimum lateral passing distance of 1.5 metres on higher-speed urban fringes, regional roads, and national primary routes.

Aerodynamic Turbulence and Air Suction Effects

When a large, high-sided bus overtakes a lightweight two-wheeler at speed, the displacement of air creates two distinct physical forces:

1. Initial Air Push: The frontal pressure wave of the bus pushes the cyclist outward away from the bus.
2. Side and Rear Air Suction: As the body of the bus passes, low-pressure turbulence along the side panels and behind the vehicle creates a powerful suction effect that pulls the cyclist inward toward the bus wheels.

If road width, oncoming traffic or lane dividers make it impossible to give the full guided clearance, the bus driver must refrain from overtaking. The driver must drop back, hold speed behind the VRU, and wait until a safe, unobstructed overtaking opportunity arises.

Micro-Mobility Hazards (E-Scooters & Personal Transporters)

The legalization and widespread proliferation of e-scooters present unique operational hazards:

• Small Wheel Diameter: E-scooters have tiny pneumatic or solid wheels that are extremely susceptible to potholes, drainage grates, expansion joints, and road debris, causing riders to lose control suddenly.
• Lack of Directional Signals: Most e-scooters lack indicators; riders may turn or change lanes unexpectedly without signaling.
• Silent Operation & Rapid Acceleration: E-scooters accelerate rapidly from traffic stops, often entering the bus’s left-side blind spot unnoticed.

---

School Zones & Bus Stop Hazard Management

Bus stops and school zones represent the highest-risk locations for pedestrian collisions involving passenger transport vehicles.

The Bus Stop Masking Effect

When a bus stops at a designated kerbside bus stop to set down or pick up passengers, it creates a massive visual obstacle (the masking effect).

• Child Pedestrian Behavior: Disembarking passengers, particularly school children, often feel an urge to cross the road immediately. Children frequently run directly in front of the stopped bus or around its rear end into the path of oncoming or overtaking traffic.
• Oncoming Traffic Hazards: Drivers approaching a stationary bus stopped on the opposite side of the road must anticipate that pedestrians may step out from behind the vehicle without looking.

Defensive Protocol When Pulling Away from Bus Stops

Before releasing the parking brake and pulling away from a bus stop, the driver must execute a systematic visual audit:

1. Scan the interior rearview mirror and passenger saloon to ensure all passengers are seated or safely holding handrails.
2. Check the left exterior flat mirror and Class V close-proximity mirror to ensure no passengers or pedestrians are near the rear wheels or passenger doors.
3. Scan the Class VI front mirror to confirm no child or pedestrian is standing in the front blind spot beneath the windscreen.
4. Check the right exterior main mirror and Class IV wide-angle mirror, signal right, and yield to passing traffic before easing into the flow of traffic.

---

Electric/Hybrid Vehicles & Acoustic Vehicle Alerting Systems (AVAS)

With the electrification of Ireland's urban bus fleets (such as zero-emission battery electric buses operating in Dublin, Cork, and Athlone), vehicle noise profiles have changed fundamentally.

The Silent Vehicle Threat

At low operational speeds (0 to 20 km/h), electric and hybrid buses produce virtually no mechanical engine noise. Visually impaired pedestrians, elderly individuals, young children, and distracted cyclists rely heavily on auditory cues to detect approaching traffic. A silent 12-tonne electric bus poses a severe hidden hazard in pedestrianized zones and urban bus stops.

Acoustic Vehicle Alerting System (AVAS) Regulation

Under EU Regulation No 540/2014 and Irish vehicle standards, all newly registered electric and hybrid Category D vehicles must be fitted with an Acoustic Vehicle Alerting System (AVAS):

• Operational Speed Window: AVAS automatically activates when the vehicle is moving from 0 km/h up to 20 km/h, as well as when operating in reverse.
• Acoustic Characteristics: AVAS emits a continuous artificial sound that mimics engine pitch and volume shifts based on vehicle speed, enabling pedestrians to judge vehicle speed and direction. Above 20 km/h, tyre rolling noise and aerodynamic sound are deemed sufficient for acoustic detection, and AVAS automatically disengages.
• Driver Vigilance: Bus drivers operating AVAS-equipped electric buses must recognize that artificial sound generators do not replace visual scanning; extra caution and lower speeds must be maintained in pedestrian-dense areas.

---

Defensive Driving & Hazard Perception around VRUs

Defensive driving around VRUs requires anticipating human error and adapting driving style to environmental conditions:

• Intersection & Roundabout Vigilance: When entering a roundabout or preparing to make a turn, always scan left mirrors for filtering motorcyclists or cyclists who may be riding straight through on your inside flank.
• Adverse Weather Spacing: In rain, ice, or high winds, cyclists and motorcyclists require significantly more road space due to reduced tire traction and stability risks. Increase passing margins accordingly.
• Quality Bus Corridors (QBCs): Where bus lanes are shared with pedal cyclists, maintain a patient, respectful distance. Never tailgate a cyclist to pressure them into moving aside.