Practical part

Choose different route sections of approximately 100 m long. Determine the number of transport units passing on the chosen section within 30 or 60 min. In this case take into account the number of vehicles of a definite type (cars, lorries, buses, diesel lorries) passing on the chosen section. If the observation takes 30 min., the result obtained should be multiplied by 2.

Calculate the average number of registered vehicles for each type of transport depending on the quantity of chosen route sections, complete Table 1.

Table 1. Average number of registered transport

Transport type	Within 30 min in total	Within 1 hour in total
Cars
Lorries
Buses
Diesel lorries

The amount of transport exhausts in the atmosphere can be determined by the calculated method. The initial data for the calculation of exhaust amount are:

• the number of vehicle units passing on the selected route section per unit of time;

– standards for transport fuel rate.

The average standards of fuel rate for urban areas are presented in Table 2.

The values of empirical coefficients (К) determining the transport exhausts in terms of fuel kind are shown in Table 3.

Table 2. Average standards of fuel rate

Type of transport	Average fuel rate (l per 100 km)	Specific fuel rate Ya (l per 1 km)
Cars	11-13	0,11-0,13
Lorries	29-33	0,29-0,33
Buses	41-44	0,41-0,44
Diesel lorries	31-34	0,31-0,34

Table 3. Values of empirical coefficients

Kind of fuel	Coefficient value (К)
	Carbon monoxide	Hydrocarbons	Nitrogen oxide
Gasoline	0,6	0,1	0,04
Diesel fuel	0,1	0,03	0,04

The coefficient К is numerically equal to the amount of emissions for corresponding compound while burnt the fuel in vehicle engine, equal to the specific fuel rate (l/km).

The result processing

Calculate the whole length of section covered by the stated number of each type vehicle per 1 hour (L_a, km) according to the formula:

L_a= N_a x L,

where N_a is the number of each type vehicle; L is the section length, km; а is the type of vehicle.

Find the amount of fuel of different kind (Q_a), burnt by the engines at this time by the formula:

Q_a = Y_a x L_а ,

where Y is the specific fuel rate (l/km); L is the length of the route section, km; а is the type of vehicle.

Determine the total amount of burnt fuel for each type of transport and complete Table 4.

Table 4. Total amount of burnt fuel

Type of transport	Qa
	Gasoline	Diesel fuel
Cars
Lorries
Buses
Diesel lorries
Total amount (ΣQ)

Calculate the volume of exhausted pollutants in litres per every kind of fuel multiplying the corresponding values of ΣQ and the empirical coefficients К. Complete table 5 with your results.

Table 5. The volume of exhausted pollutants

Kind of fuel	The amount of pollutants, l
	Carbon monoxide	Hydrocarbons	Nitrogen oxide
Gasoline
Diesel fuel
Total amount (V)

Calculate the mass of exhausts (m, g) according to the formula:

m = V x M/22,4,

where М is the molecular mass (for СО – 28, for NO₂ – 46, the average molecular mass for hydrocarbons - 43).

Determine the average daily concentration of harmful substances (С_ad, mg/ m³) in the atmosphere of the region taking into account that the volume of the air near the road section of 100 m length is approximately 20 000 m³. One should also take into consideration high traffic intensity during the day.

Compare the results obtained with MPC_СС (maximum permissible concentration) for each of the harmful substance and make a conclusion about the degree of atmospheric anthropogenic contamination of the region involved.