Cities are under increasing pressure to reduce transportation emissions, but most solutions being discussed require years of planning and significant investment.

What if you could quantify and start reducing emissions today, using infrastructure already in place? With INRIX Green Calculator, you can do exactly that for free. 

See the Impact of Congestion on Emissions  

The INRIX Green Calculator gives agencies and planners a simple way to understand: 

• How much emissions are tied to congestion and delay 
• The real impact of idling at intersections and along corridors 
• Where operational improvements could drive measurable reductions 

What makes it powerful 

Unlike traditional modeling tools, the calculator lets you interactively test real‑world scenarios by adjusting key levers such as: 

• Average delay reduction (e.g., what happens if signals are optimized by 10–20%?) 
• Traffic volume changes across corridors 
• Speed and flow improvements 
• Corridor length or network size 
• Vehicle mix assumptions (commuter vs freight-heavy routes) 

With just a few inputs, agencies can quickly see: How reducing idling and stop‑and‑go conditions directly lowers emissions.  

No complex setup. No internal data lift required. Just instant, directional insight for free. 

The Hidden Driver of Emissions: Idling at Intersections 

Once you start using the calculator, a clear pattern emerges: a significant share of transportation emissions comes from vehicles sitting still or constantly stopping and starting. 

This happens every day: 

• Cars waiting unnecessarily through cycles 
• Corridors with poor signal coordination 
• Freight vehicles losing time and fuel at bottlenecks 

The result: 

• Higher emissions 
• Wasted fuel 
• Increased driver frustration 
• Reduced network efficiency 
• Wasted money 

The question becomes: What’s the fastest way to fix it? 

Turning Insight into Measurable Emissions Reduction 

The Green Calculator shows the opportunity. INRIX Signals Analytics is how agencies capture it. Signals Analytics transforms traffic signal systems from static timing plans into continuously optimized, data‑driven operations. 

What changes with Signals: 

• Fewer unnecessary stops: Signal Analytics helps agencies identify and correct inefficient signal timing in real conditions. 
• Reduced idling time: Vehicles spend more time moving and less time emitting while stationary. 
• Improved traffic progression: Coordinated corridors reduce stop‑and‑go patterns that drive emissions. 
• Smarter prioritization: Agencies can focus on the intersections and corridors where small changes deliver outsized impact. 

Another Definition of ROI 

Historically, signal improvements were justified by: 

• Travel time savings 
• Level of service 
• Delay reduction 

Those still matter, but today’s leaders are asking a bigger question: “What impact did this have on emissions and can we prove it?” With the combination of the Green Calculator and Signals Analytics, the answer becomes clear and defensible. 

• Reduced delay and congestion 
• Lower emissions from less idling 
• Improved safety from smoother flow 
• Stronger justification for funding and grants 

From Scenario Modeling to Real‑World Results 

1. Use the Green Calculator: Estimate how much emissions are tied to congestion and idling in your network
2. Deploy Signals Analytics: Translate those modeled values intoreal‑world observations 
3. Test improvement scenarios: Adjust timing plans to improve conditions
4. Measure the outcome: Track before‑and‑after changes in delay, stops, and emissions proxies overnight or over weeks and months 

The Bottom Line 

You can’t reduce what you can’t quantify. And you can’t capture value without acting on it. 

The INRIX Green Calculator gives agencies a fast, accessible way to quantify the emissions impact of congestion and identify where improvements matter most. Signals Analytics turns those insights into action by helping agencies optimize signal performance, reduce unnecessary delay, and demonstrate measurable results.

Together, they provide a practical path to: 

• Lower transportation emissions  
• Reduce fuel waste and driver frustration  
• Improve traffic flow and safety  
• Strengthen sustainability reporting and grant applications  
• Deliver visible impact without waiting for large capital projects  

The opportunity is immediate. The infrastructure already exists. The next step is using data to make it work smarter.