At bustling intersections, the orderly flow of vehicles and pedestrians from all four directions relies heavily on the guidance of traffic lights. Without them, junctions would likely descend into chaotic “no one yields” situations, leading to frequent collisions.
Traffic lights are not merely simple signalling devices; they form the core of urban traffic management. They precisely address three major pain points: disorderly traffic flow, high accident risks, and low passage efficiency, making them an indispensable component of modern road systems.
At four-way intersections (involving motor vehicles, non-motorised vehicles, and pedestrians), traffic lights allocate rights by specifying ‘green phase durations’. For instance, a 60-second green phase for east-west traffic and a 45-second green phase for north-south traffic enables staggered passage, eliminating disorderly competition where ‘first come, first served’ prevails.
For instance, an unsignalled three-lane junction may experience over 20 vehicle conflicts per minute; a signalled junction reduces this to 5-8 conflicts, significantly improving order.
Traffic lights provide dedicated green phases for pedestrians and cyclists (e.g., 30-second pedestrian green), completely separating their crossing times from motor vehicle flows. This prevents hazardous scenarios arising from mixed pedestrian-vehicle traffic, such as pedestrians rushing across roads or vehicles making emergency evasive manoeuvres.
Data indicates that intersections equipped with dedicated pedestrian signals reduce near-miss incidents involving pedestrians and vehicles by 40% compared to those without such signals.
(1) Preventing Cross-Directional Collisions
Red lights compel vehicles in one direction to halt while permitting passage in the opposite direction, fundamentally eliminating ‘T-bone collisions’ and ‘head-on collisions’ – incidents constituting over 60% of accidents at signal-free junctions, significantly reduced with traffic lights.
(2) Reducing Rear-End Collisions
The amber light serves as a transitional signal (typically 3-5 seconds), alerting drivers to an imminent change and preventing rear-end collisions caused by sudden braking. Data indicates that intersections with amber lights experience 25% fewer rear-end collisions than those using only red and green lights.
(1) Providing Clear Warnings to Drivers
High-intensity LED traffic lights remain clearly visible even in rain or fog, prompting drivers to slow down in advance and watch for pedestrians at junctions. Countdown timers fitted to some lights also inform pedestrians of the ‘remaining time for safe crossing’, reducing the tendency to dash across.
(2) Practical Case Study
In Tokyo, intersections fitted with intelligent traffic lights (incorporating pedestrian countdown timers and speed advisory functions) saw a 38% reduction in pedestrian injury accidents over three years, demonstrating the protective role of traffic lights for vulnerable road users.
(1) Dynamic Adjustment via Intelligent Traffic Lights
Adaptive traffic lights use sensors to monitor real-time traffic flow. For instance, if 100 vehicles await in the east-west direction while only 30 are in the north-south direction, the system automatically extends the green phase duration for east-west traffic while shortening it for north-south traffic. This reduces waiting times for high-volume directions by 30%-50%.
(2) Adaptability of Traditional Fixed-Timing Signals
In areas with stable traffic flow (e.g., residential zones), fixed-timing signals can be pre-programmed with red-to-green ratios. For instance, during morning rush hour, the commuting direction receives 70 seconds of green time while the non-commuting direction gets 50 seconds, eliminating unnecessary waiting.
Without traffic lights, vehicles may face 15-20 minutes of waiting time across three consecutive junctions. An optimised traffic light system can compress this to 5-8 minutes, significantly enhancing travel efficiency.
Take Singapore's ‘Green Wave’ system as an example: by coordinating lights on major thoroughfares, vehicles can pass through 4-6 junctions without stopping, increasing average speeds by 18%.
(1) Complex Intersections (5+ Directions)
Multi-phase traffic lights separately control left-turn, straight-through, and right-turn traffic flows. For instance, the left-turn green phase activates first, followed by the straight-through green phase, and finally the right-turn green phase. This prevents overlapping conflicts between different traffic flows and is suitable for complex, high-volume intersections such as those in city centre commercial districts.
(2) Simple Junctions (Two-Way Traffic)
Basic traffic lights employ short cycle designs (e.g., 30 seconds/30 seconds), meeting the needs of straightforward junctions in suburban or rural areas without complex controls, thereby avoiding resource wastage.
(1) Priority for Emergency Vehicles
Intelligent traffic lights detect emergency vehicles such as ambulances and fire engines via GPS or sensors, automatically switching to green for their direction. This reduces emergency response times by 15-20%, securing precious minutes for life-saving interventions.
(2) Public Transport Priority
Dedicated green phases (e.g., extending green time by 10 seconds) are allocated for buses and trams, minimising delays to public transport. This encourages greater use of public transport, thereby alleviating road congestion.
(3) Temporary Construction Zones
Portable traffic lights employ short-cycle (20 seconds/20 seconds) control to guide alternating traffic flow through roadworks, ensuring worker safety while preventing prolonged vehicle congestion.
Deploying 2-3 traffic officers at an intersection incurs annual labour costs of approximately $50,000–$80,000. In contrast, an LED traffic light system requires an initial investment of just $10,000–$15,000, with a lifespan of 5–8 years and annual maintenance costs of only $500–$1,000, yielding long-term savings of 70%.
(1) Hardware durability
LED traffic lights consume only one-fifth the energy of traditional incandescent bulbs, with a lifespan exceeding 50,000 hours, eliminating frequent bulb replacements. Their IP65-rated waterproof and corrosion-resistant casings withstand harsh conditions like rain, snow, and high temperatures, reducing failure rates.
(2) Intelligent Fault Monitoring
Modern traffic lights incorporate remote fault detection systems. Issues such as bulb failure or power outages trigger real-time alerts to maintenance teams, reducing fault resolution time from 24 hours to 2-3 hours and minimising traffic disruption.
(1) Connecting to Traffic Management Platforms
Traffic lights transmit real-time data (e.g., junction waiting times, traffic volumes) to central management systems. Analysts use this data to adjust green light durations and optimise signal cycles, enhancing traffic management precision.
(2) Integration with Vehicle-to-Everything (V2X) Technology
Smart traffic lights communicate with connected vehicles, sending drivers information such as ‘remaining green light time’ and ‘red light warnings’. This reduces offences like running red lights or attempting to beat amber signals caused by driver misjudgement.
By optimising traffic flow, traffic lights reduce vehicle idling time. A single optimised junction can decrease annual carbon emissions by 12-15%, equivalent to removing 50-100 vehicles from the roads.
Concurrently, pedestrian- and cyclist-friendly traffic light designs (such as extended pedestrian green phases and dedicated cycle priority signals) encourage more people to choose sustainable travel options, aligning with low-carbon urban development goals.
Traffic signals demonstrate irreplaceable advantages in maintaining order, reducing accidents, enhancing efficiency, adapting to scenarios, lowering costs, and supporting intelligent transport systems. They serve as the ‘lifeline’ for the smooth operation of urban and rural road networks.
With advancements in artificial intelligence and IoT technologies, traffic signals will become increasingly intelligent. For instance, AI-powered traffic flow prediction and coordination with autonomous vehicles will further amplify their value in traffic management.
Should you have road construction projects (such as new urban junctions or rural road upgrades) or traffic light replacement requirements, please contact us. We offer bespoke solutions (traditional fixed-timing lights, intelligent adaptive lights, portable emergency lights), compliant with international standards including EN, FHWA, and GB. Our products come with a five-year warranty and on-site maintenance services, helping you build safer, more efficient transport systems.
