The damage to the vehicle
Bumper, paintwork, attached parts and, on newer vehicles, built-in sensors as well: collision damage in a tunnel car wash quickly reaches four figures. Two vehicles are usually affected, not one.
Vehicle tracking & collision protection for tunnel car washes
LiDAR sensors track every vehicle position in the wash tunnel in real time. When a gap becomes critical, the system stops the wash automatically — it intervenes while the situation is developing, not afterwards.
- Retrofits into existing tunnel car washes
- from €9,000 excl. VAT, plus monthly licence
Analysis from live operation
Five months, around 50,000 washes, 154 automatic stops
The figures below come from the live operation of a site in Bavaria, analysed over five months in 2026. They describe how often collision protection actually had to intervene — not how often it theoretically could.
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approx. 50,000washes over the period analysed5 months of 2026, one site in Bavaria
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154hazardous situations in which the system stopped the wash automaticallygrouped from 177 individual interventions
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1 in 324washes led on average to one situation that required a stopapprox. 50,000 ÷ 154 = 323.8
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5 of 5months with at least one hazardous situationnot a single month was free of them
Data basis. The basis is the site's system logs and its monthly wash counts. Interventions affecting the same vehicle, or one immediately next to it, within 15 minutes count as one hazardous situation. That turns 177 logged interventions into 154 situations.
What doing nothing costs
Collision damage costs more than the bodywork
Rear-end collisions in the wash tunnel do not come from technical faults but from behaviour: a customer is startled and brakes, grabs the steering wheel, drives onto the conveyor too early — or a vehicle comes off the conveyor roller while the chain keeps pulling the one behind it. Signage and instructions lower the risk; they do not remove it. And modern vehicles do not make it easier: an active emergency braking assistant will brake on its own inside the tunnel.
When it happens, it hits the business in four places at once.
The stopped conveyor
After a collision, nothing moves. The tunnel has to be cleared in a controlled way, the vehicles driven out, the queue dispersed. It does not happen when there is time for it. If it falls in a busy hour, the queue stops with it — and every vehicle in it is a customer who is waiting.
The question of evidence
Without a recording it is one account against another: did the customer brake, or did the wash keep running while a vehicle was standing still? Anyone who cannot show which it was pays when in doubt — or argues. Both cost more than the damage itself.
The site afterwards
A damaged vehicle means a customer who does not come back, and often a public review that stays up. In a market where regular customers decide how busy you are, that is the most expensive item — and the only one that appears on no invoice.
Which situations in the tunnel typically lead to a collision, and which organisational measures head them off, is set out in our guide Preventing rear-end collisions in the tunnel car wash (in German) .
How it works
Three steps from laser pulse to system stop
Vehicle tracking is an assistance system that continuously measures the position of every vehicle in the wash tunnel. LiDAR sensors scan the tunnel with laser pulses and use the time of flight of the reflected light to determine where each vehicle is, how fast it is moving and how large the gap to the vehicle in front is. If that gap becomes critical or a vehicle stops, the system intervenes in the wash controller.
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Detect
LiDAR sensors are distributed along the length of the wash tunnel and scan the detection area continuously. Unlike a photocell, which only gives a yes or no at its mounting point, this produces an unbroken picture: every vehicle position, at any moment, not just at individual switching points. Because LiDAR works with its own light source, the measurement is independent of the tunnel lighting; spray, foam and steam affect it considerably less than they affect a camera.
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Assess
The on-site server continuously calculates the gaps between vehicles and their movement relative to the conveyor from the sensor data. It recognises two patterns: a gap closing faster than it should, and a vehicle that is no longer moving with the conveyor. Both are the precursors of a rear-end collision — not its consequence.
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Intervene
If the system assesses a situation as critical, it sends the stop signal to the wash controller via a PLC module. The conveyor stops as soon as that assessment exists — while the situation is developing, not once something has happened. Every intervention is logged with time, position and movement trace and can be traced in the dashboard — weeks later too.
An assistance system — with clearly stated limits. Collision protection recognises the patterns that precede a rear-end collision and intervenes while there is still time to do so. Like any assistance system, it works within physical limits: conveyor speed, stopping distance and the moment at which a situation arises at all determine what an intervention can still achieve. No system catches a vehicle that breaks away at the last moment. Collision protection therefore replaces neither your instructions at the entrance nor your duties as an operator — it takes on the cases where until now nobody could react in time, and documents every one of them.
Where exactly the difference from a conventional photocell lies is shown by the comparison LiDAR versus photocell in the tunnel car wash (in German).
From inside the tunnel
See the system in live operation
The footage below comes from a working site. It shows no re-enacted scenes and no animation, but what the sensors actually see and how the system responds.
Several vehicles in the tunnel at once
The critical operating state of a tunnel car wash: several vehicles on the conveyor at the same time, different lengths, different positions. The system carries each of them as its own object and knows the gap to the vehicle in front at every second.
Vehicle loses the roller at the top brush
A vehicle slips off the conveyor roller while the chain keeps pulling the one behind it — the most common precursor of a rear-end collision in the tunnel. The footage shows the moment the system recognises the situation and stops the wash.
The video only loads once you expressly allow it. Until then, no connection to YouTube is made.
In daily operation
Four things that change in daily operation
An assistance system is not worth it because it contains technology, but because the working day changes measurably. These four points describe what is concretely different.
The intervention comes while the situation is developing
The system intervenes in the wash controller while the situation is building, not after it has occurred. It cannot prevent every instance of damage — no amount of braking catches a vehicle that breaks away at the last moment.
Every incident can be evidenced afterwards
Every intervention is stored with time, position and movement trace, and the dashboard history covers at least six months. If a customer reports damage days later, you can trace what actually happened during their wash instead of guessing. How the liability question is decided in a dispute is covered in our guide Damage in the car wash: who is liable? (in German)
Attention does not depend on the shift
The analysis of the Bavarian site shows this: in none of the five months did the count stay at zero hazardous situations. They occur when the site is at full capacity and staff are most tied up. The system monitors the last vehicle of the day with the same precision as the first.
You see sensor problems before they become failures
The dashboard shows the state of every sensor. The service and maintenance contract adds round-the-clock remote monitoring, with a four-hour target response time for critical faults. Three to five spare sensors are kept on your site, and replacing one after a technical fault is quickly done — you are not waiting on a delivery.
Scope
Is this the right system for you? Collision protection is right for you if vehicles can run into each other in your wash tunnel and you want to prevent that before it happens. If instead you want to show what condition a vehicle was in when it arrived, vehicle documentation is the better fit — it costs less and does not touch your controller. If what you need is to handle damage claims and maintenance records, that is the cloud platform.
Model calculation
Run the numbers on your own assumptions
There is exactly one solid figure from live operation: at the Bavarian site analysed, roughly every 324 washes produced one situation that required an automatic stop. Everything else depends on assumptions you know better than we do — how many of those situations would actually have caused damage without a stop, and what such damage costs you. Set both yourself.
Your assumption. We do not know this figure for your business — put the slider where you would place your tunnel.
In a rear-end collision, two vehicles are usually affected.
Licence and, if you choose it, service and maintenance. We state the amount for your system in the quote — until then you can enter a figure of your own here.
calculated benefit per month, after deducting the monthly amount entered
projected over twelve months
damage costs avoided per month, before deductions
hazardous situations per month
washes until the one-off investment from €9,000 is recovered
The slider is set to 40 per cent — the assumption, then, that a good one in three stopped situations would have caused damage without an intervention. We do not know how high that share really is in your tunnel; it depends on tunnel length, vehicle mix and how tightly you cycle. That is why it is a slider and not a figure from us. Feel free to calculate against yourself: at 20 per cent and €1,000 per claim — the Calculate very conservatively button — the one-off investment is still recovered within the first two months at 10,000 washes a month. It matters more to us that you can follow the calculation than that it looks impressive.
Where the figures come from. The data basis is one site in Bavaria: approximately 50,000 washes and 177 logged system interventions between February and June 2026. Interventions affecting the same vehicle, or one immediately next to it, within 15 minutes are grouped into one hazardous situation; that yields 154 situations and the rate of one situation per 324 washes.
What the calculator does. Costs avoided = washes ÷ 324 × damage rate × cost per claim. Payback is calculated against the one-off investment from €9,000 excl. VAT.
What the calculator does not do. It does not know your monthly amount — which is why you enter it yourself in the fourth field; we state it bindingly in the quote. Also not included are conveyor stoppages, goodwill payments, legal and insurance costs, and the one-off change to your PLC programming; the first three would shift the result in the system's favour, the last one against it. The rate of 1 in 324 comes from a single site and does not transfer to every system without qualification: tunnel length, customer profile and instructions at the entrance all affect it. This is a model calculation, not an actuarial assessment.
Pricing
Three components from us, one item from your PLC contractor
The pricing model is deliberately simple: you invest once in hardware and installation, after which the system runs on a predictable monthly amount per site. Collision protection starts at €9,000 excl. VAT, plus monthly licence. What your site costs specifically depends mainly on the length of your tunnel, the travel distance and the number of systems you have. We prepare your binding quote after a short conversation.
One item does not come from us. The change to your wash PLC for the stop function is carried out by your PLC contractor, who invoices you directly. We agree the interface with them and supply the specification — but we cannot put a figure on the work, because it depends on your controller and your contractor. The effort involved is limited. Ask them for that figure before you decide.
Hardware and commissioning
from €9,000
All system components for your wash tunnel: FC-LiDAR sensors, switch, server, PLC module and cabling — plus installation, commissioning and calibration on site by us. The figure depends on the length and size of the tunnel car wash and on the distance to your site.
Licence per system
in the quote
Right to use the software, ongoing updates with bug fixes and security patches during operation, access to the dashboard with real-time monitoring, system status and at least six months of history, plus baseline protection of the server.
Service and maintenance
recommended
Round-the-clock remote monitoring with proactive fault detection, regular remote calibrations without interrupting operation, free sensor replacement in the event of a technical fault including three to five spare sensors kept on your site, an annual on-site inspection and a named contact with a four-hour target response time for critical faults.
Without a maintenance contract, maintenance, calibrations and sensor replacements are charged individually as time and materials. Even a few call-outs a year then cost more than the flat rate — and proactive monitoring is missing entirely. That is why we recommend it without making it a condition.
What determines your price
- Length and size of the tunnel car wash. These determine how many LiDAR sensors are needed to cover the tunnel without gaps — and therefore the largest part of the hardware cost.
- Site and travel distance. Installation, commissioning and calibration are carried out on site by us. Distance and system size determine the effort.
- Number of systems. A volume discount applies from the second system onwards: the monthly price per system falls, and with each later expansion all systems already fitted automatically move to the new tier.
- Contract scope. Licence only or licence with service and maintenance — that is what determines the monthly amount.
- Existing infrastructure. We assume there is a network connection from the control cabinet to the equipment room and a stable internet connection. If they are missing, additional work arises before installation.
Contract and terms
- Minimum term of 6–12 months per system from commissioning, after which it can be cancelled monthly with three months' notice to the end of the month
- Payment: 50% on order, 50% on delivery
- Installation usually 3 to 6 weeks after the deposit
- The monthly costs start for each system only on its successful commissioning, not when you order; part months are charged pro rata
- Public and product liability insurance with €5 million of cover for personal injury and property damage
- The installed hardware stays in your system once payment is complete. The protective function does, however, require an active licence — if that ends, the monitoring ends
- All prices excl. VAT
Requirements
The system supplements your wash, it does not replace it
Collision protection is retrofitted into existing tunnel car washes. Your photocells keep their switching functions — entrance release, positioning, programme start — while the LiDAR tracking takes on collision protection and documentation. Replacing the wash controller is not necessary.
- A network connection from the control cabinet to the equipment room
- A stable internet connection on site for updates and remote monitoring
- The programming of your wash PLC for the stop function. This work is done by your PLC contractor; it is not part of our prices. We agree the interface directly with them and supply the specification needed.
- Space in the equipment room for the server and, where needed, a switch, plus access to the tunnel for installation
- FC-LiDAR sensors, switch, server, PLC module and all the cabling
- Installation in the tunnel, commissioning and calibration
- Setting up your dashboard with real-time monitoring and history
- Briefing your staff on the dashboard and fault messages
How long it takes
| Step | Duration |
|---|---|
| Initial call to quote — we need the site, the length of the tunnel and the number of your systems | a few days |
| Deposit to installation date | 3 to 6 weeks |
| Installation on site — we schedule disruptive work for quiet periods or after closing | 2 to 3 working days |
| Calibration in live operation — trigger thresholds adjusted remotely, without stopping the wash | first weeks of operation |
Data
Your data stays on site
Collision protection works with position data, not images: LiDAR measures distances and contours, it captures neither faces nor number plates. Everything stored beyond that — interventions, movement traces, sensor states — sits in an environment we control entirely.
Server located at your site
Hosting is exclusively on site. No cloud, no data transfer to third countries.
Encryption and access
Database encryption using AES-CBC, TLS for every connection, internal dashboard access. Configuration and calibration data are backed up in the cloud.
Objections
The questions operators ask us first
What happens if the system stops when it should not have? Does that cost me throughput?
A false stop interrupts throughput briefly; a rear-end collision shuts the tunnel down until it has been cleared — the system is deliberately set to stop when in doubt. False triggers cannot be ruled out entirely, which is why we recalibrate remotely during live operation in the first few weeks and sharpen the trigger thresholds around your vehicle and customer mix. Every stop is logged; you can look up in the dashboard why it was triggered. We deliberately do not quote a general false-trigger rate: it depends on tunnel length, system design and calibration, and a figure from someone else's site would be worthless for yours. For context, from the data we analysed: 177 logged interventions covered 154 hazardous situations — the difference comes from multiple triggers on the same situation, not from stopping without reason.
What happens if a sensor fails?
The system detects the failure itself, reports it in the dashboard and — with a service and maintenance contract — to our remote monitoring. How the system behaves in that state, whether it continues with reduced coverage or stops, is something we agree with you at commissioning; that is an operational decision, not a technical rule. Three to five spare sensors are kept on your site for replacement, and if the fault is technical, the replacement is free under the maintenance contract. So you are not waiting on a delivery, and your system is not standing still because of a spare part.
Can this be retrofitted to my existing system, or do I need a new controller?
Retrofitting is the normal case. The sensors are mounted in the existing tunnel, the server sits in the equipment room, and the stop signal goes to your existing controller via a PLC module. You do not replace your system controller. What you need to provide: a network connection from the control cabinet to the equipment room, a stable internet connection, and the change to your PLC programming by your PLC contractor. That last item is not included in our price — but we coordinate directly with them.
I have photocells. Why is that not enough?
A photocell gives you a yes or no at exactly one point. Between two points the controller is blind — and that is precisely where rear-end collisions happen: a vehicle brakes, comes off the conveyor roller or stops, and the system only finds out when the next photocell trips or when the impact has already happened. LiDAR measures continuously across the whole detection area. There is a second point: a photocell cannot prove anything in a dispute, whereas a recorded movement trace can: it shows you where each vehicle was at which moment and whether the system intervened. Whether that is accepted as evidence in a particular dispute is not for the system to decide but for the individual case. You do not have to replace your photocells because of this — they keep their switching functions.
You will find the detailed comparison in our guide LiDAR versus photocell (in German).
Do foam, spray or darkness interfere with the measurement?
Hardly. LiDAR is an active method with its own light source and is therefore independent of the tunnel lighting; the measurement works in a dark tunnel just as it does at a bright exit door. Spray, foam and steam affect it considerably less than they affect a camera. LiDAR is not free of physics either: heavily soiled sensor optics degrade measurement quality. Regular cleaning is therefore part of the deal. We choose mounting positions so that the sensors are not in the direct spray.
Who is liable if the system does not detect a situation?
Collision protection is an assistance system, not a safety component within the meaning of machinery safety law. It supplements your responsibility as the operator and that of the customer, it does not take it over — installing it changes nothing about your duties as an operator, your customer instructions or your signage. We would rather say this plainly than have you find it out when a claim arrives. Our public and product liability insurance with €5 million of cover applies to personal injury and property damage arising from our work — a fault in installation or configuration, for example — not to the operation of your tunnel car wash.
How long is my system out of action for the installation?
Installation usually takes 2 to 3 working days. The system is not normally out of action during that time: part of the work — cabling, setting up the server, configuring the software — runs alongside normal operation, and we schedule the work inside the tunnel for quiet periods or after closing. We agree the sequence with you beforehand. On more complex systems it can take longer; we say so before you place the order, not during it.
What will this actually cost me in the end?
From €9,000 excl. VAT as a one-off for hardware and installation, plus a monthly amount per system for the licence and, if you choose it, for service and maintenance. We state the exact monthly amount in the quote, because it depends on system size, contract scope and the number of your sites — a volume discount applies once you have several systems. The monthly costs start on successful commissioning, not when you order. The minimum term is 6 to 12 months per system, after which it can be cancelled monthly with three months' notice to the end of the month. All amounts are excl. VAT.
Guides
Practical knowledge for operators
Liability, technology and cost — answers to the questions that really come up in daily operation. Our guides are written in German.
Safety
Preventing rear-end collisions in the tunnel car wash
The most common causes in the wash tunnel and which organisational and technical measures genuinely help.
Technology
LiDAR and photocell compared
What both detection technologies deliver in the wash tunnel — and when moving to LiDAR is worth it.
Law & liability
Damage in the car wash: who is liable?
When the operator pays, when the customer does — and why the question of evidence almost always decides it.
Other systems
Two systems that connect directly to this one
Collision protection acts inside the tunnel, before a situation turns into damage. These two systems act before and after it.
Vehicle documentation & ANPR
Tracking evidences what happened inside the tunnel. Vehicle documentation evidences what condition the vehicle was in when it arrived — the other half of the same question of evidence, and the cheaper entry point, because it does not touch your controller.
from €5,000 excl. VAT — read more →Cloud platform for car wash systems
Every damage claim, and many other processes, become a case that has to be handled, answered and filed. That is exactly what the platform is for — on German servers rather than in a messaging group.
Price range after an initial call →Do you also run a vacuum area? Vacuum bay monitoring measures occupancy and dwell time for each bay. And if your case fits none of these systems: custom systems.
Next step
Three details are enough for a solid quote
We need neither an on-site audit nor weeks to produce a concrete quote. Have these three details ready and we can tell you in the first conversation whether and how your tunnel can be retrofitted — and what range the price will be in.
- Site and approximate length of your tunnel in metres (a plan of the wash tunnel)
- Manufacturer and model of the wash system and of the controller in use
- The number of systems you want to fit
You speak directly to the developer and owner, not to a call centre. If collision protection does not make sense for your system, we will tell you in the same conversation.
Available Monday to Friday, 9am–4pm · info@flowcontrol.de