Decoding Bengaluru Traffic Signals VAC , MNL , INL

If you've ever driven through Bengaluru, you've likely noticed VAC, MNL, and INL flashing on traffic signals. While most people understand the basic red, yellow, and green lights, these acronyms often leave commuters puzzled. But these signals are more than just letters—they represent advanced traffic management systems designed to improve flow, reduce congestion, and adapt to real-time conditions.

What Do VAC, MNL, and INL Mean?

Bengaluru’s traffic signals operate in three distinct modes, each serving a unique purpose: 

• VAC (Vehicle Actuated Control) – Smart, AI-driven signals
• Uses CCTV cameras and sensors to detect vehicle density at intersections.
• Adjusts signal durations dynamically based on real-time traffic flow.
• Reduces unnecessary wait times and improves efficiency.
• Operates automatically but may require manual intervention during peak hours.

• MNL (Manual Mode) – Traffic police-controlled signals
• Activated when officers override automated systems.
• Used during VIP movements, emergencies, or extreme congestion.
• Can lead to longer wait times, as manual adjustments may not be as precise.

• INL (Intelligent Mode) – Pre-programmed signal cycles
•    - Works on fixed durations without external intervention.
•    - Used in areas with consistent traffic patterns.
•    - Less adaptive than VAC but ensures predictable signal timing.

With over 900 traffic junctions, Bengaluru faces severe congestion, especially in high-density areas like Outer Ring Road, Silk Board, and Whitefield. Traditional signals fail to adapt to fluctuating traffic conditions, leading to longer commutes and bottlenecks.

To combat this, the Bengaluru Traffic Police (BTP) has implemented AI-powered Adaptive Traffic Control Systems (ATCS) across 41 junctions, with plans to expand to 165 junctions by year-end. These systems integrate VAC technology, ensuring real-time traffic adjustments.

 How Effective Are These Signals?

• VAC signals operate automatically 94% of the time, but require manual intervention (6-17%) during peak hours.
• Manual signaling has reduced from 40% to 3-4% at most junctions, improving efficiency.
• AI-driven signals have been installed at key locations like KR Road, Hudson Circle, and Town Hall Junction.

Despite these advancements, manual overrides remain necessary for ambulance movement, VIP convoys, and unpredictable congestion spikes. With AI-driven traffic control expanding, Bengaluru is moving toward fully automated intersections, reducing reliance on manual signaling. The goal is to:

• Minimize congestion by optimizing signal durations.
• Enhance commuter experience with real-time traffic adjustments.
• Reduce pollution by preventing unnecessary idling at signals.

As more junctions adopt VAC and ATCS, Bengaluru’s traffic system will become smarter, faster, and more efficient. Understanding VAC, MNL, and INL isn’t just about decoding signals—it’s about recognizing how Bengaluru is evolving to tackle one of its biggest urban challenges: traffic congestion. The next time you see these acronyms flashing, you’ll know exactly what they mean and how they’re shaping the city’s future.