Baroxon Ireland | Boom Barriers & Vehicle Access Control
Vehicle Detection Compared: Inductive Loop vs Radar vs Photocell vs ANPR
Release time:
2026-10-19
Inductive loops remain the most accurate vehicle presence detector at 99.5%, but radar matches them on moving-vehicle detection with no road cutting. Use a loop where the pavement can be opened, radar where it cannot, and treat photocells as safety devices rather than triggers.
Presence detection is what tells the barrier when it is safe to close. Get it wrong and the arm drops onto a vehicle, or stays open for an empty lane. The four technologies behave very differently.
Inductive loop detectors
A loop of insulated wire is buried in a saw cut and sealed, and the detector measures the inductance shift caused by ferrous mass above it. Loops are the reference technology: they detect stationary vehicles, are unaffected by weather, and are insensitive to pedestrians. Their cost is the road work.
Microwave radar
A radar head mounted on the barrier cabinet or a pole transmits a continuous wave and evaluates the Doppler and range signature. Radar installs in minutes with no pavement work and handles motorcycles and bicycles better than a loop, but it detects movement rather than static presence, so a vehicle that stops inside the beam may be lost.
Infrared photocells
Photocells are through-beam or retroreflective devices. They are cheap and instant, but they see a single line and are defeated by dirt, fog, low sun and by the vehicle itself if the beam is placed badly. Their correct role is safety, not triggering.
ANPR as a detector
Where the lane already carries an ANPR camera for access control, the camera can also act as the trigger. This removes hardware but adds a dependency: if the plate is unreadable because it is dirty or absent, the lane does not open. Always provide a fallback.
Verified performance data
Condition: 500 vehicle passages, dry pavement. Result: loop 99.5% detection, radar 97.0%, photocell 94.0%. Benchmark: below 95% the lane needs manual override more than once per 100 vehicles.
Condition: installation time per lane. Result: radar 15 minutes, loop 45 minutes plus curing. Benchmark: 30 minutes is the typical lane-closure budget in a live car park.
Condition: response time from target entry to output. Result: loop 10 ms, radar 30 ms, photocell 5 ms. Benchmark: 50 ms is negligible against 1.2 s barrier opening.
Condition: powered two-wheeler detection. Result: radar 98%, loop 85%. Benchmark: 90% is the practical minimum where motorcycles use the lane.
Recommended configurations
- New construction, concrete available: presence loop plus a safety loop, or loop plus photocell.
- Existing pavement, no cutting permitted: radar for triggering, photocell pair for safety.
- ANPR-controlled lanes: camera as primary, radar or loop as fallback.
- Residential drives: radar or loop, plus photocell where children or pets are present.
FAQ
Why does my radar miss a car stopped at the barrier?
Because it detects motion. Either select a radar with a static-presence mode, or add a photocell across the lane to hold the arm open.
Can a loop be repaired without breaking the pavement again?
Usually the fault is at the feeder joint or the detector, not in the buried loop. Test the loop inductance first: if it measures within 50 to 500 microhenries, the loop is intact.
Do I still need photocells if I have a loop?
Yes. The loop tells the controller a vehicle is there. The photocell is a monitored safety input that keeps the arm from closing on a pedestrian or a vehicle tail.
Latest News
Boom Barrier Duty Cycle Explained: What 100% Duty Cycle Really Means
Duty cycle is the single specification that decides whether a boom barrier survives a toll lane. This guide explains how duty cycle is measured, how to size it from your traffic pr...
2026-10-19
Boom Barrier Motor Types Compared: AC Induction vs Brushless DC vs Servo
AC induction, brushless DC and servo drives are the three motor technologies used in boom barriers. This comparison covers cycle life, efficiency, noise, cold-start behaviour and c...
2026-10-19
EN 12453 and EN 12445 Compliance for Power-Operated Gates in the EU
Power-operated gates and boom barriers placed on the EU market must satisfy the Machinery Directive 2006/42/EC. EN 12453 defines the required safety levels and EN 12445 the test me...
2026-10-19
ANPR Camera Placement: Engineering a 99% Plate Read Rate
Automatic number plate recognition accuracy is decided by geometry before it is decided by software. This guide sets out the capture angles, plate resolution, shutter speed and ill...
2026-10-19
Barrier Arm Length vs Opening Speed: The Engineering Trade-off
Opening speed and arm length pull against each other through a single constraint: tip speed. This article explains the trade-off, when to specify articulated or folding arms, and h...
2026-10-19
Vehicle Detection Compared: Inductive Loop vs Radar vs Photocell vs ANPR
Inductive loops, microwave radar, infrared photocells and ANPR cameras can all trigger a barrier. This comparison covers detection accuracy, installation disruption, response time ...
2026-10-19
Baroxon Ireland | Boom Barriers & Vehicle Access Control
Advanced Security Access Control and Intelligent Parking Solutions.
Company Strength
Adequate Inventory
Fast Shipping
Our Products
CONTACT US
Address: Baroxon EU Service Centre, Dublin, Ireland
© COPYRIGHT 2025 Baroxon Ireland | Boom Barriers & Vehicle Access Control
WhatsAppScan the QR code to chat with us
WeChatScan the QR code to follow us
Contact Us
Our passion is to bring your ideas to life. Work with our design team to create a one-of-a-kind custom finish or cladding system to create a truly unique space. Together we can make your story stand out. If you need something to request a sample, request pricing, or request a demo, please fill out the contact form below. Explain your request in as much detail as you can and a representative will contact you within 1 business day.