How to Operate Underground or Multi-storey Car Parks

The operation of underground and multi-storey car parks presents unique challenges and considerations compared to surface-level parking facilities. These facilities, whether they’re high street car parks serving shoppers or central car parks catering to office workers, are vital parts of urban infrastructure, particularly in city centres where space is at a premium.

Ventilation and Air Quality

One of the most critical aspects of operating an underground or multi-storey car park is maintaining adequate ventilation. Vehicle emissions in enclosed spaces can quickly build to dangerous levels without proper air circulation. Modern facilities use a combination of natural ventilation (where possible) and mechanical systems controlled by carbon monoxide sensors. The sensors trigger increased fan operation when CO levels approach prescribed limits—typically maintaining levels below 30 parts per million for long-stay areas and below 60 parts per million for short-stay zones, as recommended by British Standard BS 7346-7.

Fire Safety

Fire presents a particularly serious risk in enclosed parking structures. UK regulations require specific fire safety measures in multi-storey car parks, including fire detection systems, emergency lighting, clearly marked escape routes, and ventilation systems capable of smoke extraction. Many modern facilities incorporate sprinkler systems, though these are not mandatory in all cases. Fire exits must be positioned so that no point in the car park is more than 45 meters from the nearest escape route, in line with Building Regulations Approved Document B.

Lighting

Good lighting is essential for both safety and user comfort. Unlike surface car parks that benefit from natural light during daytime hours, central car parks with underground or covered facilities require constant artificial illumination. Energy-efficient LED lighting has become the standard, often paired with motion sensors that adjust light levels based on occupancy. This can reduce energy consumption while maintaining safety standards.

Good lighting makes people feel safer; poor lighting is likely to deter people (especially women) from using the car park.

Traffic Flow and Layout

Good design and management of traffic flow is important, particularly in busy high street car parks where there is frequent turnover of vehicles. One-way systems are common, using clear directional markings and signs to guide drivers. Ramps between levels need careful consideration; the gradient should ideally not exceed 1:10 (10%) for straight ramps or 1:12 (8.33%) for curved ramps to ensure safe access for most vehicles. Space is often at a premium, so an efficient layout of parking bays is vital while still maintaining adequate room for manoeuvring.

Car parks are notorious for creating low-speed manoeuvring accidents, so layouts need to be wide enough to allow for realistic turning circles. Parking bays need to be wide enough to accommodate larger vehicles. Also remember that people (in general) are getting larger, and it’s more difficult for them to enter and exit their vehicles; car parks that were laid out 20 years ago are often no longer feasible in terms of allowing enough room for vehicles to open their doors wide enough.

Payment Systems and Access Control

Modern multi-storey car parks typically employ automated payment systems, from simple pay-and-display to more sophisticated automatic number plate recognition (ANPR) systems. These can be integrated with barrier controls and payment machines to create a seamless user experience. Some high street car parks now offer contactless payment options and smartphone apps for booking and payment.

Security

Security is a major consideration, particularly in underground facilities where natural surveillance is limited. CCTV coverage, good lighting, and regular security patrols are standard features in central car parks. Some operators employ 24-hour staffing, while others rely on remote monitoring and emergency call points. The British Parking Association’s Park Mark scheme sets standards for security in car parks and can be a useful benchmark for operators.

Maintenance

Regular maintenance is crucial for both safety and longevity. This includes structural inspections (particularly important in underground facilities where water ingress can be an issue), cleaning, and maintenance of mechanical and electrical systems. The damp environment typical of underground car parks can accelerate wear and corrosion, requiring more frequent maintenance than surface facilities.

Environmental Considerations

Car park operators are increasingly focusing on environmental impact. This includes the installation of electric vehicle charging points—a growing necessity as the UK moves towards its target of ending new petrol and diesel car sales by 2030. Some multi-storey car parks are also incorporating sustainable drainage systems (SuDS) to manage water runoff and green technologies such as solar panels where feasible on above-ground levels.

Commercial Viability

The higher construction and operating costs of underground and multi-storey facilities must be balanced against potential revenue. Prime high street car parks can command premium rates, but operators need to consider local competition, accessibility, and target market (short-stay shoppers versus long-stay commuters, for example) when setting pricing strategies.

Operating an underground or multi-storey car park requires careful attention to multiple factors, from safety and security to user experience and commercial considerations. Success depends on striking the right balance between these various elements while maintaining compliance with relevant regulations and standards.