The emission source of automobile exhaust pollutants is calculated as follows:

\(Q=∑^n_{i=1} NiEi/3600000\)

In the formula:

Q-contaminant emission source intensity, g/m•s;

N-the total number of road vehicles;

Ni-i type car traffic, vehicle / h;

The Ei-i type vehicle exhaust comprehensive emission factor, g/km, is regarded as the speed of the medium-sized vehicle. The recommended value of the medium-sized vehicle emission factor is 50km/h. HC3.29g/km., CO42.27g/km., NOX4.18g/km.

Vehicle exhaust gas coefficient for different road types

<table class="pure-table"> <tbody> <tr> <td width="83">Road type</td> <td width="82">Average speed</td> <td width="159">CH4（Kg/set one kilometer）</td> <td width="140">CO（Kg/set one kilometer）</td> </tr> <tr> <td>Big road</td> <td>16</td> <td>0.006</td> <td width="140">0.099</td> </tr>

    <tr>
      <td>road</td>
      <td>29</td>
      <td>0.004</td>
      <td>0.059</td>
      </tr>
    <tr>
      <td>highway</td>
      <td>39</td>
      <td><p>0.004</p>
      </td>
      <td>0.048</td>
      </tr>
      <tr>
      <td>highway</td>
      <td>72</td>
      <td>0.002</td>
      <td>0.028</td>
      </tr>
    </tbody>

</table>