Stagnoli traffic light control units are the benchmark technological solution for eliminating the risk of collision and ensuring safe evacuation in multi-storey car parks and high-density residential complexes. Installing a traffic regulation system turns a simple access ramp or an alternating one-way lane into an active safety system, capable of interfacing directly with the building's alarm systems. In settings with reduced visibility and limited manoeuvring space, traffic light automation prevents vehicle congestion, drastically reduces the build-up of exhaust gases (CO) and prevents accidents.
Safety as a Priority: A Multi-Storey Residential Case Study
Effective flow management in underground car parks requires deterministic access control, particularly in multi-storey structures with helical or straight single-lane ramps. In a recent project in a residential and office complex with more than 150 parking spaces, the implementation of Stagnoli control units met the twofold need to keep traffic flowing smoothly at peak times and, above all, to secure the entire infrastructure in the event of an emergency.
The main operational issue was the high risk of vehicles becoming blocked along the main ramp during simultaneous entry and exit manoeuvres. The control unit was configured to manage magnetic loop presence sensors and infrared photocells, determining right of way absolutely and preventing deadlock situations that would have delayed emergency vehicles or hindered the evacuation of occupants.
Safety Traffic Light Logic and Reverse Operation in Emergencies
The technical operating principle of these traffic light control units is based on programmable priority logic that instantly switches to “safety mode” when a critical event occurs. The relationship between normal and emergency operating states is strictly defined to protect human life:
Normal Operating State (Alternating Logic): the control unit gives green to the first vehicle that triggers the detection sensor, immediately switching the opposite traffic light to fixed red until the vehicle has completely cleared the occupied area.
Fire Alarm State (Reverse Mirror Logic): when the
smoke or fire detection system is activated, the Stagnoli control unit receives a priority blocking signal. The
standard logic is bypassed: all entrance traffic lights instantly switch to Fixed Red (to prevent new vehicles from entering the danger zone), while the traffic lights along the evacuation routes switch to Fixed or Flashing Green (to guide and speed up the evacuation of cars already inside the car park).
Regulatory Framework and Fire Safety Compliance
The compliance of automation systems for car parks depends on observing the ministerial decrees governing fire safety and worker protection. The modern performance-based approach requires control units to be integrated into the building's overall safety plan.
| Reference Regulation | Scope of Application | Requirement / Impact on the Traffic Light Project |
| D.M. 3/08/2015 (Fire Prevention Code) | Civil and industrial buildings | Promotes the performance-based approach: the traffic light is an integral part of evacuation and escape route control systems. |
| D.M. 15/05/2020 | Car parks with a surface area > 300 m² | Mandatory vertical technical regulation. Requires controlled flow management so as not to hinder evacuation in the event of fire. |
| Circolare VV.F. 17496/2020 | Car parks with a surface area < 300 m² | Guidelines for structures below the threshold, which nevertheless require the risk of blockages along the ramps to be minimised. |
| D.M. 01/09/2021 e 03/09/2021 | Workplaces (e.g. company car parks) | Governs inspection, the keeping of registers and the mandatory periodic maintenance of active safety systems. |
Specific Benefits for Safety and Design Professionals
Adopting Stagnoli traffic light control units offers tangible guarantees to those responsible for design and safety:
For Designers and Engineers (Building/Civil): Easy integration into BIM and fire prevention projects thanks to full compliance with the specifications of D.M. 15/05/2020 for the management of transit ramps.
For Health and Safety Managers (RSPP): Objective reduction of the risk of pedestrians and vehicles being struck in company manoeuvring areas and a guaranteed controlled evacuation flow in emergencies.
For Installers: Intuitive wired and wireless architecture, removable terminal blocks and integrated LED diagnostics for fast, error-proof commissioning.
For Business Owners and Property Managers: Legal protection resulting from full compliance with the maintenance and inspection obligations imposed by D.M. 01/09/2021, together with the reliability of industrial components designed for intensive use (Heavy Duty).
FAQ – Frequently Asked Questions
What happens to the traffic light control unit in the event of a power outage or fire alarm?
In the event of a fire alarm, the interface with the fire alarm control panel blocks access (fixed red at the entrance) and facilitates exit (green along the evacuation route). In the event of a power outage, if combined with a suitable uninterruptible power supply (UPS) or backup battery, the control unit maintains the emergency logic or switches to flashing amber hazard mode, preventing deadlock.
When is it mandatory to apply D.M. 15/05/2020 for traffic management in a car park?
D.M. 15/05/2020 is the mandatory reference technical regulation for all car parks, whether newly built or being upgraded, with a covered surface area of more than 300 m².
Do car park traffic lights require periodic maintenance?
Yes. In workplaces, or where the traffic-light-controlled ramp is classified as an escape route or vehicle safety system, D.M. 01/09/2021 and 03/09/2021 require scheduled periodic inspections and the recording of all work in the fire safety or maintenance register.
Why use mirror/reverse logic in an underground car park?
Because standard alternating logic is designed for smooth flow under normal conditions, whereas mirror (or blocking) logic physically prevents new cars from entering an area filled with smoke or flames during an emergency, safeguarding drivers' lives and making the work of the Fire Brigade easier.
Ensure maximum safety and full regulatory compliance for your multi-storey car park.
Contact our technical department to request a fire prevention consultation, analyse the regulatory framework and receive a customised project with Stagnoli traffic light control units.