In performance reporting terms, the traffic light rating acts as a visual indicator of performance. Also known as RAG (because of the red, amber and green colours), traffic light icons are commonly used in dashboards and other kinds of performance reporting to tell us where performance is on track and where attention is needed.
With such a simple way of presenting information, you might think it&#;s hard to get it wrong. Unfortunately, that&#;s not the case. In my experience, traffic light ratings are commonly misused and misinterpreted.
Where companies go wrong with KPI traffic lights
There are three main ways traffic lights are misused in performance reporting. Firstly, what I see most often is massive overuse of traffic lights &#; whether on a dashboard or in a report, what&#;s presented is a long list of KPIs with traffic light colours next to them, displaying either red, amber or green. The trouble with listing so many RAG ratings on one page or screen is that people quickly suffer from information overload. If we&#;re being directed to 50 pieces of information at once, we feel stressed, we find it hard to identify the most important information, and we come away with no valuable insights.
Secondly, because the traffic light colours are seen as so intuitive, companies don&#;t always take the time to clarify what each of the RAG ratings mean. For example, when you see an amber icon, does that mean performance is not great but it&#;s okay? Or does it mean that attention is required in this area? Or does it act as an early warning that performance might be going off-track? Unless you clearly state the meaning for each colour, the traffic light ratings are open to interpretation.
And thirdly, I&#;ve learned over the years that people HATE seeing red on a dashboard or in a report when it relates to their area of responsibility. Red puts people on the defensive. They&#;d rather see green, green and more green. As a result of this instinct, people can be tempted to twist the interpretation of KPIs just so they can get that all-green screen. When you start doing that, performance reporting becomes meaningless. So I always stress to companies that it&#;s important to strike a balance between red and green in reporting &#; red shouldn&#;t be avoided like the plague. Red ratings are a great opportunity to flag up areas that require attention, attract resources where needed and, above all, improve performance.
Using traffic lights effectively in your performance reporting
Having looked at some of the biggest pitfalls of using traffic light colours in performance reporting, let&#;s look at how to avoid those issues and use traffic lights in a smart, effective and meaningful way. Here are my top tips:
Traffic light ratings can be a useful addition to KPI reporting, but only if they&#;re used carefully, and sparingly! Follow these tips for using traffic light colours effectively and you can better engage people in performance metrics, and help them to improve performance in the future.
Where to go from here
If you would like to know more about KPIs and performance management, check out my articles on:
Or browse the KPI Library to find the metrics that matter most to you.
Traffic signals play a vital role in the busy modern urban traffic network. Traffic lights are power-driven traffic control devices that display lights that instruct traffic to take specific actions. They can guide vehicles, pedestrians and other traffic participants to pass in an orderly manner, effectively reducing traffic conflicts and congestion. Ultimately, it improves the safety of vehicle users and pedestrians and makes the most efficient use of available road space. We will list the classification and functions of traffic signals one by one, as well as the composition and working principles of traffic lights at typical intersections. In addition, the concept of &#;phase&#; of traffic lights is the core of understanding their working principles and traffic flow organization, which determines the order and duration of different traffic flows. This article aims to provide readers with a comprehensive and in-depth knowledge system of traffic signals, so as to better understand this seemingly simple but crucial traffic facility.
The function of traffic signals is to control the movement of traffic, bicycles and pedestrians, especially at intersections, and to alert road users to special safety issues (for example, at level crossings or in front of schools). Traffic signals should achieve some or all of the following purposes:
Traffic signals are an important tool for directing road traffic. They can be divided into many types according to their functions and locations. Common types of traffic lights include:
ItemMotor vehicle traffic signalsPedestrian traffic signalsArrow traffic signalsCountdown timerPhotosThe motor vehicle traffic signal consists of three circular(full ball) units of red, yellow and green patterns. It has three complete (circular) faces and indicates that vehicles can pass the relevant stop line under the instruction of the relevant green face lighting, but it does not impose any restrictions on direction, etc. Its main function is to guide the passage of motor vehicles, that is, the red light indicates prohibition of passage, the green light indicates permission to pass, and the yellow light indicates slow travel or warning.
With competitive price and timely delivery, FAMA sincerely hope to be your supplier and partner.
Pedestrian signals are traffic signals designed specifically for controlling pedestrian traffic. Pedestrian facilities should be provided to improve the safety of pedestrians crossing the road. They are usually installed at intersections controlled by traffic signals. It provides pedestrians with a phase at which signals can be issued to take care of the needs of pedestrians. Pedestrian traffic signals can be activated by a relay pedestrian button or automatically (for example, to prevent the phase from being inconsistent with adjacent signals on the connected signal system). It also consists of red, yellow (if available), and green circular units with bicycle/pedestrian patterns inside. It is generally set at both ends of the crosswalk. When the red light is on, pedestrians and non-motor vehicles are not allowed to enter the crosswalk/intersection; when the green light is on, pedestrians and non-motor vehicles can pass.
When it is necessary to control vehicles for a specific movement (usually a left turn), a second traffic signal head may be set up next to the signal head that controls the movement of adjacent traffic. The second head should display red, amber and green arrows instead of full aspects. This arrangement avoids the more obvious full red aspect, which only stops the turn when other traffic has a green aspect. The arrow can point left or right, or upward to indicate straight-line movement. It uses arrow traffic signals to indicate different directions of vehicle or pedestrian flow to more accurately control traffic flow and direction.
In places where there are a large number of motor vehicles or long waiting times, in addition to red, amber and green digital signals, countdown timers can also be installed on each side of the intersection. Using the remaining time displayed by the traffic light countdown timer, drivers can turn off their engines while waiting for the red light, which helps reduce fuel consumption. When the red light is about to end, drivers can use the remaining time displayed by the traffic light countdown timer to start the vehicle in advance, thereby shortening the start time and improving the traffic capacity of the intersection. It can also be set up next to non-motorized vehicles and pedestrian signals. This type of timer system provides drivers and pedestrians with an accurate countdown, increasing road flow, reducing congestion at intersections and ultimately improving traffic conditions.
Next, we discuss traffic signal phase-related concepts, standard phase schemes, and discuss their impact on traffic efficiency and safety. A &#;signal phase&#; is the complete sequence of green, yellow, and all red indications that give an action (including going straight, turning left, or turning right to the east, west, north, or south). Each of the green, yellow, and all red cycles that make up a phase is called a &#;phase interval.&#; The series of signal phases that serve all possible movements at an intersection is a &#;cycle.&#; A cycle can consist of as few as two phases or as many as eight (or more) phases. The phase state list details the color state of the signal light (such as red, green, yellow) and its duration in that phase. The number of phases at an intersection depends on the specific conditions of the intersection, including factors such as the shape of the intersection, the number of lanes, and the traffic volume. Common phases include standard two phase operation, standard four phase operation, and standard eight phase operation.
Traffic signal phaseThe simplest type of signal phase is the standard two-phase operation. Here, the main street entrances to the intersection are served by phase one and the secondary street entrances are served by phase two. The two-phase configuration is very efficient and works well in low-volume conditions, but does not allow for a separate turn phase, so two-phase systems are less commonly used at intersections with a high volume of turning (left-turning) traffic. Two-phase signals are often found in urban and rural areas where left-turn volume is low to moderate.
Traffic signal two or four phase operationIn order to provide an independent left turn phase when there are a lot of left turn movement, a four-phase signal controller is designed. In a four-phase signal, all phases are continuous, which means that no two phases can be activated at the same time. It usually does not allow the movement within a phase to be timed separately, or in other words, the signal cannot enter the next phase until all movements within the current phase have timed out or interrupted. Its overall structure is called a &#;loop&#; because after completing a cycle, it returns to phase 1 and starts again. A typical four-phase plan is shown in the figure below.
Four-phase operation allows left turns to be handled individually, but does not allow for individual timing of each (different) action within a phase. This is important in situations where the relative volumes of a phase are unbalanced, where four-phase operation will maintain a phase even if one of the actions no longer has any demand. Eight-phase operation allows for individual timing of each action, for more efficient operation.
An eight-phase controller is like two four-phase controllers working together. As with a four-phase controller, phases 1-4 form one ring. Phases 5-8 form a second ring, so eight-phase controllers are often called &#;dual-ring&#; controllers. Each ring operates in sequence, meaning that at any time only one phase in a ring can be active and timed separately from the phases in the other ring. Phases can be skipped if there is no demand. All phases in a given ring should be collided. Each ring operates independently, with the only restriction that both rings must cross the barrier together. That is, any phase (1 and 2) in ring 1 on the left side of the barrier can be matched with any phase (5 and 6) in ring 2 on the left side of the barrier. However, any phase (1 and 2) in ring 1 on the left side of the barrier cannot be run together with any phase (5 and 6) in ring 2 on the right side of the barrier.
Standard eight phase operation &#; traffic signalsThe signal configuration of an intersection needs to consider many factors, such as traffic volume, intersection size, number of lanes in different directions, and functional requirements. Among them, the motor vehicle traffic signals (fall ball red, yellow, and green) need to be set up with a set of three-color signal lights in each direction. If there are multiple lanes, the number can be increased appropriately to ensure that drivers in all lanes can clearly see the signal. For example, a four-way intersection with one or more lanes in each direction requires at least 4 sets of traffic signals. If the intersection allows left or right turns and has a dedicated turning lane, arrow traffic signal lights should be set up and each direction usually requires at least one left turn arrow traffic signals(right turn arrow traffic signals &#; if requires). That is, a four-way intersection requires up to 8 arrow signal lights (two in each direction, one left turn and one right turn). Countdown devices are usually installed next to motor vehicle traffic signals or pedestrian traffic signals to help drivers and pedestrians understand the remaining waiting or passing time. Generally speaking, a four-way intersection requires at least 4 countdown devices. If the intersection design includes non-motorized vehicle lanes or dedicated bicycle lanes, each direction requires a non-motorized vehicle traffic signals and two pedestrian signals. Below is the signal light configuration at a typical intersection.
ItemsModelPhotoProductLED QtyAt each entrance to an intersection, vehicles have three directions they can go which is called moves: right, through, or left. Right and through are usually grouped together as a single move, so a typical four-way intersection has eight vehicle and four pedestrian moves. These moves can be grouped into phases of a traffic signal. For example, left turns in opposite directions can be grouped into a single phase because they can be done at the same time without conflict. Traffic engineers use circle and barrier diagrams to outline how the signals operate in different phases. Here is a ring and barrier diagram for our example intersection. Phase 1 is for left turns in the north-south direction, and phase 2 is for straight travel in the north-south direction. Note that the timing of the opposite direction moves in phases 1 and 2 can be inconsistent, i.e., a south-to-north left turn can end early and be replaced by a north-to-south straight move. But there is a barrier between phases 2 and 3, so they must end at the same time. Phase 3&#;s east-west left turns and phase 4&#;s east-west straight moves also operate in the same way, so we won&#;t go into detail here. The following diagram will give you a better understanding of the different moves in the four/eight phases.
How do traffic signal workThis article mainly introduces the main functions of traffic signals, the classification of different traffic signals, and the composition and distribution of typical crossroad lights. We also introduce the theory of traffic signal phases and understand their actual application and application characteristics in intersections. At the same time, we also apply these theories to typical intersections to help us understand the working principles of traffic lights, etc. I hope that everyone can deepen their understanding of traffic lights through this article, suppliers can better serve customers, and customers can better and more accurately choose signals to arrange their own projects. Contact us for more information.
Traffic phases are defined as the green lights, changes, and gap intervals assigned to a specified traffic movement in a cycle. So traffic phase is different from traffic cycle. Normally a cycle contain 2, 4 or 8 phases. And a cycle is defined as the total time to complete the signal sequence of all movements of different phases at an intersection.
Traffic lights have three colors: red, yellow, and green. When the light turns red, you must stop, when it turns yellow, slow down and wait, and when it turns green, go.
The meaning, sequence and rules of traffic signals are basically the same in all countries. Red light: Stop and wait at the stop line. Red and yellow lights: Be ready to move, but don&#;t go until the green light turns on. Streetlight: If it&#;s safe, you can go. Give way to pedestrians crossing the street.
My name is Taylor Gong, I&#;m the product manager of ZGSM Tech. I have been in the LED lights industry for more than 13 years. Good at lighting design, street light system configuration, and bidding technology support. Feel free to contact us. I&#;m happy to provide you with the best service and products.
: [ protected] | : +
Want more information on aspect traffic light? Feel free to contact us.