About Traffic Indexes

Please note that the indices provided in this section are based on user-contributed data. We aim to provide a platform for individuals to share their experiences and perceptions regarding traffic conditions in their respective cities. It is important to understand that these indices rely on subjective opinions and may not reflect official or comprehensive traffic statistics. However, they can still offer valuable insights into the overall traffic situation and commuting experiences in different locations. We encourage you to use these indices as a general reference and complement them with other reliable sources, if available, for a comprehensive understanding of traffic conditions.

Traffic Index is a composite measure that that considers factors such as commute time, dissatisfaction with time spent in traffic, CO₂ emissions, and overall traffic system inefficiencies. It provides insights into the overall traffic conditions in a city.

Time Index represents the average one-way daily commute time required in minutes. It provides an indication of the time it takes to travel from one place to another within a city.

Time Exp. Index is an estimation of dissatisfaction due to long commute times that assumes that dissatisfaction with commute times increases exponentially with each minute after a one-way commute time is longer than 25 minutes.

Inefficiency Index estimates inefficiencies within a city's traffic system. High inefficiency typically indicates a preference for private car use over public transportation or excessively long commutes. It can be used as a traffic component measurement in economic analyses.

CO₂ Emission Index estimates CO₂ emissions attributable to daily commute by passenger. The measurement unit is grams for the return trip. To calculate an average CO₂ emission in grams for one-way commute, divide this value by 2.

Actual formulas to calculate indices are subject to change. At this moment, quite complex empirical formulas are used. Those formulas, as written in the Java programming language, are as follows:

  protected void calculateIndex() {
    index = new TrafficIndex();
    index.time = overall.getTimeOverall();
    double tooMuchTime = 0.0;
    if (index.time > 25.0) {
      tooMuchTime = index.time - 25;
    }
    index.timeExp = index.time + Math.pow(tooMuchTime, Math.E);
    double co2 = 0.0;
    co2 += overall.time_bus * 20.0; // bus produces 20g of CO2 per minute (for each passenger)
    co2 += overall.time_driving * 133.0; // car produces 133g of CO2 per minute (assumes only driver)
    co2 += overall.time_train * 10.0; // train produces 10g of CO2 per minute (for each passenger)
    co2 += overall.time_tram * 15.0; // tram produces 15g of CO2 per minute (for each passenger)
    co2 += overall.time_other * 10.0; // other produces 10g of CO2 per minute
    co2 += overall.time_motorbike * 80.0; // motorbike produces 80g of CO2 per minute
    index.co2 = 2 * co2; 

    index.main = index.time + Math.sqrt(index.timeExp) + Math.sqrt(index.co2) + Math.sqrt(index.inefficiency);
}

To estimate number of trees to cover CO₂ consumption, we assume 240 days of commuting during the year and we are using the cite "A single tree can absorb CO2 at a rate of 48 lb. per year." - Arbor Enviromental Alliance.
As java formula formula:

    double co2CommuteConsumptionYearly = 240 * index.co2;
    double treesNeededForCommute = (co2CommuteConsumptionYearly / 1000) / 21.77;  //each tree absorbs about 21.77kg of CO2