Chicago’s Accessible Pedestrian Signal rollout has moved ahead of court-ordered installation targets, with more than 78 intersections equipped in the first year. Yet the same report notes that technical gaps remain, including issues that can affect whether blind and low-vision pedestrians receive the safety benefit these systems are intended to provide.
That tension is familiar to traffic engineers. At an intersection, installation is only one layer of performance. The operating environment around the device matters: turning vehicles, signal phasing, approach delays, pedestrian clearance time, right-turn behavior, peak-period demand, and how all of those conditions change across the day, week, and season. This is where an intersection study becomes more than a count. It becomes a diagnostic framework for whether the intersection is actually functioning as designed.
Ticon’s intersection analytics are built for that operational layer. In Ticon Turns: verification of accuracy, Ticon describes a proprietary turning movement estimation method based on multivariate analysis of GIS, traffic events and management data, demographics, traffic statistics, connected vehicles, traffic organization, location-based services, traffic detection, and GPS or navigation data. The output is turning movement traffic demand for each 15-minute period across a 24-hour day, with aggregation available by day of week, weekday versus weekend, month, season, year, peak period, or off-peak period.
That level of temporal detail is important for accessibility projects because pedestrian safety treatments do not operate in a vacuum. An APS may be correctly installed, but if the surrounding traffic pattern includes heavy right-turn demand during school dismissal, commuter peaks, or evening retail activity, the crossing environment changes. A static inspection can confirm whether the button, locator tone, and audible message work. An intersection study can show whether the traffic movements around that crossing create delay, conflict pressure, or timing needs that vary by time of day.
Ticon’s Turns product supports this type of study by providing true average daily traffic values, intraday flow distributions, HCS-compatible formats, turning movement volumes, right-turn travel delays, by-approach delay, and intersection-level demand and delay metrics. The distinction is practical. Many conventional studies rely on a few hours or a few days of manual counts or portable detectors. Ticon’s approach is based on continuous 24/7/365 observation for the exact intersection, with results kept current to within about one week rather than depending on the last available field count, which may be years old.
The engineering value is not only coverage, but also validation. In Ticon Turns: verification of accuracy, Ticon compared its turning movement estimates with portable detector measurements collected by the Androscoggin Valley Council of Governments at two three-leg and two four-leg intersections in Maine. The study evaluated left, through, and right movements at 15-minute resolution. Ticon calculated relative error and normalized relative error, with the normalized metric weighting errors by the traffic volume in each 15-minute interval so that low-volume nighttime periods were not treated the same as peak demand periods.
The observed discrepancy between Ticon estimates and portable detector measurements was in the 7 percent to 22 percent range. The white paper concludes that Ticon turning movement count estimation can keep expected error within 25 percent boundaries, a result the report describes as practical for most ITS applications. That range also reflects a known limitation of short-term field counts: previous research cited in the paper indicates that short-term traffic flow measurement can shift by approximately plus or minus 25 percent. In other words, a short count and a month-long empirical profile may differ because the road itself is variable, not simply because one measurement is “wrong.”
For intersection accessibility work, this matters. A single inspection window might miss the period when the crossing is most difficult to use. A morning count might not represent evening pedestrian demand, weekend entertainment traffic, construction detours, weather-sensitive behavior, or school-day turning patterns. Ticon’s broader traffic volume methodology addresses the same problem at the network scale. In Ticon intraday traffic volumes estimation, Ticon reports an AADT median average percentage error of 4.78 percent and a relative root mean square error of 11.97 percent, keeping expected volume estimation error within 20 percent boundaries with 90 percent confidence. The same report evaluated 490 daily sets of traffic volume values, representing more than 47,000 paired comparisons.
Those figures support a central point for intersection studies: reliable operations analysis requires both spatial and temporal resolution. Ticon’s methodology provides coverage for more than 97 percent of roads at functional road class 6 and above, and estimates speeds and volumes for 95 percent of roadways at fine spatial resolution, down to short segments of up to 35 feet and about 225 feet on average. This helps avoid a common problem in traffic analysis, where a nearby detector is used as a proxy for an intersection that may have a different turning mix, different land use, and different pedestrian exposure.
The cost and labor implications are also material. Ticon’s report All-directional approach to Traffic Signal Optimization notes that even an ordinary intersection may have up to 12 directions, and that preparing high-quality signal optimization with conventional methods can require about 50 hours of work by a transportation engineer per intersection. That workflow includes monitoring all approaches, collecting turning movements, accounting for seasonal and weekly variation, building an analytical model, and calculating optimal timing tables for multiple intervals.
For a city managing hundreds or thousands of intersections, that manual burden limits how often timing plans can be refreshed. It also limits how quickly agencies can respond when accessibility upgrades, new pedestrian phases, transit changes, or land-use shifts alter the operating balance. Ticon’s continuous observation model reduces that dependency on isolated field campaigns and gives engineers a more current basis for deciding whether an intersection needs retiming, additional study, or targeted field inspection.
The signal timing implications are clear. In Ticon’s research on adaptive traffic signal control, based on observations from more than 250 intersections on urban roads and suburban arterials in the United States and Europe, the company found that only 24 percent of modeled cases could be effectively accommodated with six timing plans per week. For 76 percent of cases, up to 24 different timing plans could be necessary. This finding reinforces the point that intersections are dynamic systems. A single timing plan or a narrow count window rarely captures the range of operating conditions that affect vehicles and pedestrians.
For APS deployments, the engineering lesson is not that analytics replace accessibility inspection. They do not. Device placement, audible message clarity, pushbutton reach, locator tone performance, vibrotactile confirmation, and maintenance compliance still require direct technical review. But intersection analytics can show where those devices sit within the traffic system. They can identify whether right-turn delay, approach imbalance, peak-hour turning volume, or recurring congestion may require a timing adjustment or a closer field review.
A well-executed intersection study connects infrastructure to operations. It shows not only what has been installed, but how the intersection behaves when people actually use it. For cities expanding APS programs, bus priority, bike crossings, leading pedestrian intervals, or coordinated arterial timing, that distinction is essential. The next generation of intersection management will depend on combining compliance-focused field inspection with continuous empirical measurement of traffic demand, turning behavior, and delay. That is the space where Ticon’s methodology gives planners and engineers a stronger basis for safer, more efficient, and more inclusive streets.
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