Inputs
Enter base route and detour assumptions. Use optional factors to match site conditions.
Example data table
| Scenario | Base distance | Detour distance | Base speed | Detour speed | Stops / Signals | Queue | Added time (approx.) |
|---|---|---|---|---|---|---|---|
| Urban closure | 10 km | 14 km | 50 km/h | 40 km/h | 2 / 3 | 2 min | ~10–14 min |
| Rural diversion | 18 km | 26 km | 70 km/h | 60 km/h | 1 / 0 | 1 min | ~7–11 min |
| Work-zone corridor | 8 km | 11 km | 45 km/h | 35 km/h | 3 / 2 | 4 min | ~15–22 min |
Examples are illustrative; your field inputs override these assumptions.
Formula used
The calculator estimates baseline and detour travel time, then computes the additional delay.
BaseTime(min) = (BaseDistance / BaseSpeed) × 60AdjustedDetourSpeed = DetourSpeed × (1 − WorkZoneReduction%/100)DetourCruise(min) = (DetourDistance / AdjustedDetourSpeed) × 60DiscreteDelays(min) = Stops×StopDelay(sec)/60 + Signals×SignalDelay(sec)/60 + QueueDelay(min)HVPenalty(min) = DetourDistance × (HeavyVehicles%/100) × HVPenalty(sec per unit)/60DetourTime(min) = (DetourCruise + DiscreteDelays + HVPenalty) × PeakFactor × WeatherFactorAddedTime(min) = max(0, DetourTime − BaseTime)
Peak and weather multipliers represent congestion and reduced operating speeds.
How to use this calculator
- Choose a unit system that matches your reporting.
- Enter base and detour distance plus average speeds.
- Add expected stops, signals, and any queue time.
- Apply work-zone reduction, peak, and weather factors.
- Review added minutes and apply the suggested buffer.
- Download CSV or PDF to share with the field team.
Baseline versus detour comparison
The calculator converts distance and average speed into minutes, then contrasts the normal route against the detour route. This makes the “added time” value useful for shift start buffers, material deliveries, and emergency access planning. If the detour distance is similar but speed is lower, the time impact can still be significant. For recurring haul trips, enable round trip to double both routes and align totals with daily truck counts.
Intersection and control delays
Stops and signal delays model interruptions that do not appear in cruise speed. Typical field planning values range from 15–60 seconds per stop and 25–90 seconds per signal, depending on cycle length and side-street priority. Queue delay captures merge friction at lane drops, temporary tapers, or narrow bridges. When you have flagger timing, use the average waiting time rather than maximum red time to avoid overstatement.
Work-zone speed reduction effects
Speed reduction applies directly to the detour speed before delays are added. A 10% reduction on a 40 km/h detour reduces effective speed to 36 km/h and increases cruise minutes by about 11%. Use this when the detour includes gravel segments, tight radii, active equipment crossings, or pedestrian control.
Peak and weather multipliers
Peak and weather factors scale the full detour time to reflect demand and operating conditions. A peak factor of 1.15 is common for morning congestion, while 1.30–1.60 can occur near schools, markets, or constrained urban corridors. Weather factors of 1.05–1.20 can represent reduced visibility and cautious driving. Document the chosen factors in your work package so supervisors can revisit them after the first day’s observations onsite.
Heavy vehicle share planning
Truck and bus proportions affect acceleration, grade performance, and gap acceptance at intersections. The heavy-vehicle penalty is a practical linear allowance tied to detour distance. For example, 20% heavy vehicles with a 12-second per km allowance adds 0.04 minutes per km, which becomes meaningful on long diversions. Export the CSV or PDF to attach assumptions to traffic control documentation.
FAQs
What distance and speed values should I enter?
Use realistic averages from recent trips, GPS logs, or site reconnaissance. Enter full route distance, not straight-line distance. Speeds should reflect typical moving conditions, excluding long stops that you will model using stop, signal, or queue inputs.
How do I choose a peak factor?
Start with 1.05–1.15 for mild congestion and increase if the corridor is routinely saturated. If field observations show detour travel takes 20% longer than expected, set the factor near 1.20 and revise after monitoring results.
What if the detour includes multiple slow segments?
Lower the detour speed to match the overall average, then apply a work-zone reduction if active controls further reduce flow. You can also increase queue delay for the most restrictive segment to reflect intermittent backups during peak periods.
Does queue delay replace stops and signals?
No. Queue delay is for sustained backups and merge friction. Stops and signals represent repeated interruptions at discrete points. Use all three when they occur together, but avoid double-counting by keeping each input tied to a distinct observed delay source.
How should I set the heavy vehicle penalty?
Use higher penalties for steep grades, tight turns, and frequent intersections where trucks accelerate slowly. If you lack data, begin with 10–15 seconds per distance unit and refine after one day of hauling by comparing measured times with the estimate.
How do I export and share the results?
After calculating, use the CSV download for spreadsheets and the PDF download for briefings or permit packages. Exports include your inputs and summary outputs, helping stakeholders understand assumptions and the added minutes expected during closure operations.