Operations-wise, the LIDAR teams locate and most often conceal themselves at the shoulder, over a nearby flyover, the median or behind the columns or earth embankments of overpasses. Sometimes they park on the opposite carriageway even if their targets are over the opposing lanes. The teams take care not to have their LIDAR "field of view” obstructed or interfered by stray reflections from metal guard rails or billboards. The camera equipment are modern “set and forget” i.e. they will not turn on or issue a speed reading if the LIDAR's operation has not been confirmed/verified for calibrated accuracy via GPS monitors. Neither will the LIDAR post any reading if visibility is poor as in heavy fog or rain. Or the car is just too fast for the camera's shutter, in which case if a speed reading is taken without a car image. In the latter case, there can be no prosecution — no image, no ID, no evidence, no ticket.
Positive ID required
These mostly American-branded Taiwan- or China-made speed monitoring equipment use non-SLR point and shoot digital cameras because the photo of the vehicle plate number is mission critical to produce proof of speeding. Handheld speed guns that only show speed readings without a photo are not usually admitted as evidence in court. Even the simple mathematical computation of distance over time for speed between toll gate entry time and exit time on the tollway ticket is not always admissible as evidence in traffic court as it doesn't produce positive ID of the driver. There was a time was when the digital image of the speeding offender was available on a website, but now, such are only available when a defendant's attorney requires it.
Steady as she goes
For best operations, the LIDAR equipment should be mounted on a tripod and should remain stationary while operating. In fact, the LIDAR camera should not even be used to “pan” or follow a target vehicle as it was not designed for such use, even if the manufacturer claims that the equipment can be used handheld. It has been proven that handheld use has led to reading inaccuracies as the field of aim varies on the surface of the subject vehicle, or worse, the focal point gets confused if 2 different vehicles are running side by side.
Nocturnal speed checks
NLEx has video-based LIDAR equipment specifically designed for night operations without using a flash, but patrols deploy them rarely. For night use, SLEx MATES take care that the flash doesn't blind the offending driver by switching to rear plate number aim as the car recedes whereas daytime operation is usually aimed at approaching vehicles. But even when mounted on a tripod, wrong readings can still happen.
The speeding Volvo
In mid 2015, there was this case of the “speeding Volvo” on the SLEx that hit close to half a million mostly sympathetic hits on social media. Having been successively arrested for speeding, Doc Dennis brought his wife as a witness and recorded via iPhone his car's speedo reading and time of night they travelled between Caltex Mamplasan to Calamba. With the Volvo's speedo indicating a steady 100km/h, the LIDAR camera dutifully flashed in the median vicinity of Eton City. By Calamba, the Volvo was pulled over for speeding at 131km/h. The arrest was insisted but the SLEx's MATES officers were stumped by the iPhone evidence and also the distance over time computation as per the iPhone's time and GPS speed tracking which resulted in a speed slower than the Volvo's 100km/h. It would be interesting to know how the judge of the traffic court decided on this one.
To get the MATES' side of the story, an intrepid journalist of a popular local car magazine arranged a “drive-by” simulated speed trap in the day and posted his attempt on social media. The intrepid journalist cum test driver held a steady indicated 110km/h on his Miata's speedo. The LIDAR camera was situated in the median by Santa Rosa. Approaching the LIDAR, the Miata showed a speed of 113km/h but as the car receded from rear facing LIDAR, the reading dropped to 103km/h. It only proves the case of equipment error in Doc Dennis's Volvo speeding violation.
Not a pleasant job
Make no mistake, tollway operators, almost to a man, derive no joy in lording it over the intimidating process of hailing a speeder to book. Though controlling speeding shows a commitment to safety, tollway security personnel deputized by the LTO do not relish the experience of arresting drivers who, like them, admit to preferring to drive a little bit faster than the ridiculously low legally-mandated posted speed limit. These arresting officers are mistaken to be motivated by income-producing fines, which only go to the LTO. Besides, all tollway operators prefer to promote road safety through less confrontational and more positive means like rescuing breakdowns and guiding motorists on lane discipline and lane change behavior.
Many worse offenders
Many a “victim” of the LIDAR speed gun bewail that the most common infraction on our tollways are the left lane huggers. These are more numerous and are a genuine obstruction to smooth expressway travel. Many of these left lane huggers are under the impression that since they are driving at the 100km/h legal limit, they have a right not to be overtaken and that anyone who passes them are obviously breaking the law.
Holier than thou?
In fact, left lane-hugging is a violation as the rules of the road require that once an overtake is done with, the driver must return to the right most lane. Whatever the speed. The problem is that these violations are not easy to catch. To do so needs cruisers or patrols that the NLEx calls “lane managers”. These vehicles are equipped with a loudspeaker to warn the erring left lane-hugging driver to return to the right lane. Moreover, these vehicles also have a variable message sign at the rear to give instructions and warnings to erring drivers. Stubborn violators are due for a pull over and a ticketing, but to complete the picture, there has to be evidence beyond a patrolman's say so. Enter today's inexpensive dash-cams. These video cameras can provide the lane manager/patrol with the necessary evidence to prove the refusal or stubbornness of left lane huggers to yield the left lane, or worse, to continue to block it despite repeated warnings.
According to the LTO left lane-hugging falls under another LTO catch-all traffic violation called “obstruction”. Thus left lane hugging is bunched up with offenses like blocking a yellow box intersection, parking on a zebra crossing, parking on a corner, etc. As an offense, “obstruction” is lower down the food chain and hence commands a cheaper fine, if we are not mistaken. Perhaps, left lane hugging should be elevated to reckless driving as it does induce irritated drivers to engage in reckless driving like — passing on the right, flashing high beams, riding the rear bumper or tail gating and excessive horn blowing — to graphically warn the left lane hugger to pull over. Perhaps some may not agree, but the pedants among those who hate left lane-hugging have likened it to illegal counterflow.
Lastly, while we are on the subject of summer vacation and long weekend travel season plus (sorry to be a spoiler), the tollway congestions that it triggers, it doesn't mean that with lowered average speeds, the speed cameras are not at work. In fact tollway operators mount speed monitors on critical sections of the expressway to check if the average speeds are getting slower and that dangerous bunching of traffic into impromptu “trains” or “convoys” is materializing. The speed monitors also check if there are slow pokes who block traffic by driving below the minimum allowed speed. The danger of these impromptu “close-coupled” convoys is that most drivers used to urban stop-and-go driving revert to their city habits; refusal to yield and following too close to refuse/block merging traffic.
Keep safe distance
Those NLEx signs that say KEEP SAFE DISTANCE is no mere sloganeering. With speeds still faster than city traffic stop-and-go, keeping too close to the bumper of the vehicle being followed reduces the reaction time and space to stop the car in case of any sudden stops ahead of the convoy. These situations are ripe for multiple vehicle tail-to-nose collisions that block highways for hours. Also, these impromptu convoys trigger the impatient to overtake on the emergency shoulder or the grassy median.
The French connection
To discipline the impromptu traffic convoys and manage speed during the August summer vacation traffic, the Autoroute Gendarmes of France assign a marked patrol car to lead such forming convoys. When conditions permit, these patrol cars lead at close to or slightly above the legal speed limit in an effort to keep traffic moving at an even and predictable pace. Mind you, this is another way of driving fast without getting a speeding ticket. Just don't overtake the lead Gendarmerie mobile unless you really want a speeding ticket.