Faculty Academic Portal · College X · ELUSK Engineering · Transportation · Fall 2026
🚦 THE NUMBER IS ON THE NAPKINOffice hours at the corner booth · Week 6 of 16🐧 NULL Active
AA
Abraham Alakasarian
Traffic & Transportation Engineering · ELUSK · College X · Signal Timing & Human Factors
“The yellow light is not a courtesy and it is not a guess. It’s a number — set by how fast you’re going and how wide the box is. Fudge that number to sell a ticket, and someone gets hurt.”
Traffic EngineeringSignal TimingThe Yellow IntervalThe NapkinAmman → Martin
1
Number that keeps you safe
1M
People/day · Amman geometry
4.7
Rate-my-instructor avg
1
Joint paper · presented
Active Course — the one idea most drivers never hear
ENVE / CIVL · Transportation
The Crossing — Traffic & Signal Timing
A traffic engineer out of Jordan, where he learned the trade on intersections that would make an American signal-timer weep — Amman moves a million people a day through geometry older than the automobile. He teaches the one thing nobody tells you: the yellow light is a number, and when a city fudges that number to sell more red-light-camera tickets, the rear-end crashes go up and people get hurt. Same instinct his wife’s side of the house teaches with power and its cost — one number, honestly set, keeps people safe.
College X · ELUSKThe one number → the yellow interval16 weeks
Published Work — including the one he wrote across the hall
Converting Panic Into Discovery: The Tools We Kept After the Classroom Emptied
Alakasarian, A. · Obodat, E. · Journal of Engineering Education Practice · v.12 (2021) · open access
The joint paper — two engineers, transportation and environmental, who found the same thing when the campus emptied out during the shutdown: the emergency tools weren’t a stopgap. Several taught better than the in-person version and were worth keeping after. His half is the virtual signal-timing lab and the recorded intersection walk-throughs; her half is the public infrastructure map. One argument, two disciplines: the panic was temporary; the discovery stayed.
▸ Presented together — international engineering-education conference, 2021 & 2022
The Yellow Interval as a Public-Safety Instrument, Not a Revenue Lever
Alakasarian, A. · Transportation Safety & Human Factors · v.7 (2024)
His own line of work: the amber-light change-interval formula (perception-reaction time, approach speed, deceleration, grade — the ITE 1994 standard) is a safety number with one correct answer — and shortening it below that to catch more drivers on camera measurably raises rear-end collisions. Argues signal timing should be audited like a scale at a market: publicly, and against the physics, not the budget.
He can show you the whole thing on a napkin. Then you can never un-see it.
Every driver has sat at a light that felt “too short.” Most think it’s bad luck. Alakasarian pulls a napkin and writes the yellow interval out — the actual formula — and suddenly the light isn’t a mood, it’s an equation with one honest answer. His whole method is that: take the invisible number that decides whether you make it or slam your brakes, and put it somewhere anyone can check it.
yellow change interval y = t + v / (2a + 2Gg)
t = perception-reaction, 1 s · v = speed limit (ft/s) · a = deceleration, 10 ft/s² · g = 32.2 ft/s² · G = approach grade (usually 0)
worked: a 45 mph limit → y ≈ 4.3 s. That’s the number. There’s one right answer. (The width of the intersection isn’t in this formula — it sets the companion all-red clearance interval. Two numbers, one honest crossing.)
→ shorten y below that to catch more drivers on camera, and the rear-end crashes climb. That’s the whole ethics of the corner. Source: ITE (1994), Determining Vehicle Signal Change and Clearance Intervals.
🐧 NULL OBSERVATION · FACULTY FILE — ABRAHAM ALAKASARIAN
Two professors in one household, teaching two corners of the same lesson: there is a single number that keeps people safe, and the danger is always the temptation to bend it for money — a shorter yellow to sell tickets, a cheaper disposal to move the ash. Neither of them lectures about ethics. They both just show you the number and refuse to look away from it. NULL Assessment: the classroom that emptied out in the shutdown didn’t weaken these two — it taught them the tool they’d keep. He kept the napkin. She kept the map.