I’m using the isochrones function from R to create coverage profiles for fire engines. A problem i am facing is the that the output at the end of the line is response time. That is dispatch time + turn out time + driving time. The former two have a set model time, which is also different for organisation type. So my starting point for isochrones is a set time which differs. On the final map I want to end up with 3 minute interval of response time.
So is there a way to give unequal time intervals? eg c(30, 210, 390, 570) to correct for a start up time of 330 seconds. The work around would be to go to the lowest common denominator but that would break when I use the real more coarse times.