Passage detectors work properly, but sometimes people use them for actuated control, and they’re not very good for that. Passage detectors only detect a vehicle once when it crosses the detector. If a vehicle is standing over the detector, a passage detector is not aware of it. Because of this, actuated signals that don’t work with passage detectors often simulate correctly with presence detectors. Input data files that use passage detectors for surveillance purposes seem to work correctly.

Each object category has a checkbox next to the name that can toggle all objects of that category on or off.

Possible causes for the unexpected exit volumes may include stochastic randomness, surface street queue spillback, or interference from interface nodes. Regarding stochastic randomness, exit fractions might become more accurate after averaging the results from multiple runs with different random number seeds. Regarding surface street queue spillback, this sometimes prevents vehicles from exiting the freeway. Regarding interface nodes, FRESIM has trouble predicting the number of vehicles entering from those locations. When this happens, exit percentages can be adjusted to give better results.

After a vehicle has crossed the warning sign for its exit, it is allowed to use any HOV lane that leads to the exit, even if it doesn’t qualify to use the HOV lane.

The green phase of a FRESIM ramp meter often lasts 1 second; but the first vehicle in queue, or the first two if “two per green” is enabled, is allowed to proceed and then ignore the signal. In some cases the problem is a lane drop warning sign, which is located directly on top of the node where the ramp meter is located. It will work if the warning sign is moved 1 foot downstream to allow vehicles to respond to the ramp meter and then respond to the lane drop, instead of trying to respond to both of them at the same point. In other cases, Startup Delay should be changed on the ramp metering link. For example, a Startup Delay of 0.1 seconds will sometimes produce much higher capacities than a Startup Delay of 1.0 seconds.

The traffic assignment logic requires that all signalized or uncontrolled intersection approaches actually have vehicle volume on them. Also note that traffic assignment cannot be performed for CORSIM files containing FRESIM links.

Sometimes when no vehicles are allowed to go thru, the user does not specify the thru receiving link. Because the thru receiving link is not specified, CORSIM doesn’t check to see if there are any vehicles on it that would block the left-turners. The conflict checking logic and the spillback checking logic in CORSIM need to know all of the receiving links, even when no vehicles will turn onto one or more of those receiving links.

Some techniques for avoiding premature actuated phase termination in NETSIM are as follows:

  1. The gap reduction code should be ’0′ instead of ’2′.
  2. The maximum initial interval should be equal to the minimum green.
  3. Min recall should be activated to avoid phase skipping, if phase skipping is not desired.
  4. The minimum gap should be 2.0 seconds or higher.

You can use the Output Processor to get the Travel Time Per Vehicle MOE for each link in either NETSIM or FRESIM. The Output Processor will export the selected MOEs to an Excel spreadsheet, or a file of some other format. The Travel Time Per Vehicle link MOEs can be summed to get the average travel time from the start node to the end node. This method will include travel times for turning vehicles as well as through vehicles on all links. To get a better estimate of the travel time it is possible to get the Travel Time Per Vehicle by turn movement and use the appropriate MOE for each link in the path. Note that the average will be based on all vehicles that traveled on the selected links, not necessarily vehicles that complete the entire trip from first node to last node. You can use the Output Processor in TSIS 6.