title: SUMO: Change simulation time step and output option
body: <p>I am running SUMO for a large network for up to 4 days. I understand thta most traffic following models were developed in second but I kind of need to increase the timestep to minutes or 5/10 mins.  </p>
  
  <p>I have come across this function. <a href="https://sourceforge.net/p/sumo/mailman/message/32876223/" rel="nofollow">https://sourceforge.net/p/sumo/mailman/message/32876223/</a></p>
  
  <pre><code>&lt;time&gt;
      &lt;step-length value="3600" /&gt;
  &lt;/time&gt;
  </code></pre>
  
  <p>However, when I used it, it doesn't seem right. Yes, per step each vehicle does travel much further than it does with a smaller timestep. Th issue seems like only one or two cars can departure each time which overwrites the <code>step-length</code> function.</p>
  
  <p>Can someone tell me how to set a different timestep and are there another setting I need to change to make it right?</p>
  
  <p>Another question is I am getting a very large <code>xml</code> output file, however, I only care about the last timestep or certain timesteps. So I am wondering are there any possible way I can choose only to output last timestep or selected timesteps?</p>