Traffic operations teams must continually work to maintain optimal signal performance within their cities, often despite limited staff and budget constraints. The prioritization of staff and resources is an ongoing consideration, particularly regarding the maintenance and retiming of traffic signals. With so many important goals tied up with the success of traffic signal optimization, such as improving congestion, reducing emissions, and promoting public safety, it is easy to see why. Traffic operations managers hoping to make the most of their department’s time and budget will need to strategize around high-value opportunities. This blog series explores the many use cases of INRIX Signal Analytics in helping agencies achieve their goals.

The Three Categories of Urgency

No two cities are the same, but for many agencies, signal maintenance prioritization generally falls into three distinct groups of signals within the system. 

High Profile, High Volume 

First and foremost are the 10-15% of signals that an agency already knows are a problemDuring peak periods, these are the signals that are notably oversaturated, have a very high public profile, and are usually responsible for the majority of the phone call complaints that come in. The opportunity to improve them without investing into additional infrastructure is unlikely, but not impossible. However, agencies would need insight into whether these signals are truly oversaturated or if something specific is actually broken.

Lightly Traveled and Low Urgency 

On the opposite extreme are the 10-15% of signals that are typically low volume and managed well. These signals are more than likely operating at a high level of performance with well-timed or traffic responsive control, and probably won’t need any attention. In fact, when crews show up during regularly scheduled maintenance dates, it’s entirely possible that the time and energy could be better spent elsewhere.

Everything Else 

This leaves the remainder of the city’s traffic signals, which fall somewhere between the two groups of extreme urgency and low priority. This middle group of signals can sometimes go unnoticeddespite representing a significant portion of overall delay. It could be months or even years before an engineer is able to arrive and retime them appropriately. There are tangible benefits to retiming signals of this nature ahead of their planned maintenance dates, even if they aren’t the subject of public scrutiny, but the fact that agencies can’t respond to them sooner means a lot of potential value is being left out in the field.

Urgency versus Opportunity 

Agencies have finite time and resources to maintain optimal signal timing each year. The challenge so far has been directing staff to where they can produce the most value. Traffic operations teams already have infrastructure in place to collect and evaluate traffic data. What’s missing is an effective method of evaluating priorities from a high level across entire systems. What would it look like if operations managers knew exactly which signals were experiencing performance degradation? What kind of impact would that have on overall performance metrics, budget, and vehicle emissions?

The Solution: INRIX Signal Analytics 

To get that kind of information on a daily basis, agencies need to think beyond physical infrastructure and consider cloud-based connected vehicle solutionsINRIX Signal Analytics utilizes connected vehicle probe data to map out entire cities, giving agencies a high-level glance into which intersections are performing adequately.

Daily automated reports provide traffic operations managers with the means to prioritize maintenance projects based on which signals have recently experienced a dip in performance, as opposed to strategizing around responding primarily to public outcry or waiting for 3 to 5-year maintenance cycles. From the dashboard, agencies have a high-level view of system performance, including average control delays and performance changes of individual intersections. This gives traffic operations managers a general idea of system-wide level of service with the option to drill into a particular area if a problem appears to be emerging.

Prioritizing Staff and Resources

With INRIX Signal Analytics, agencies can prioritize their efforts in a scalable and detector free approach that isn’t currently possible with conventional ATSPMs. Using the color-coded map view, traffic operations managers can readily identify the signals that have experienced the most performance degradation, based on data delivered through daily reports. Managers can derive granular insights, including through movement and turn levels of service, vehicle and stop counts, or overall control delays, all of which tell an important story of not just where underperforming signals exist but what might be the cause. Using the corresponding signal analytics tool from our partners at The Center for Advanced Transportation Technology Lab (CATT Lab), agencies can easily create before and after studies, or customize time ranges to identify performance discrepancies.  

The benefits of vehicle probe data intelligence are two-fold: agencies can prioritize staff and resources around the highest net returns, and they can minimize budget spend on intersections that are already performing perfectly. Over time, with a value-based response strategy that minimizes unnecessary work, agencies will observe a notable ease in budget pressure. 

Without the right tools in place, agencies can expect more of the same challenges—limited visibility into system-wide signal performance and prioritizing tasks around external pressure instead of high-value opportunities. With the support of a vehicle probe data solution, traffic managers will have a better idea of how to best prioritize their staff and resources to curb budget pressure over time.

This blog post is part of a content series explaining use cases of INRIX Signal Analytics. INRIX is a pioneer in mobility data solutions. To see how INRIX Signal Analytics can help your organization, schedule a free demo here.