By: Michael Horoho | Date: 11/27/2025 01:50:37 PM
Late October, early November, the City of Noblesville placed a stealth box on Tulip Tree Drive to monitor the speed patterns of vehicles traveling in and out of the Trailside Woods neighborhood for one week. It was conducted by Andrew Rodewald, City Engineer, who provided the results in the emails listed below.
In summary, 212 vehicles were recorded with the majority of the vehicles traveling the speed limit of 25MPH or less. Andrew stated that we were in the 85th percentile which indicates 85% or more were driving the speed limit. This is considered safe by the City of Noblesville and does not warrant any other action by the city. There were 4 vehicles that were recorded over 40MPH and any other vehicles over the speed limit would have been traveling under that. Andrew cannot share the exact details but did say that although the majority of the vehicles were traveling safely, it is still a good idea to occasionally remind everyone to continue to drive with caution with the large number of children in our neighborhood.
Please let the Board know if you have any questions or concerns at ([email protected])
Original email from Andrew Rodewald:
Tony,
We have had a chance to take a look at the data from the traffic study that was performed. We set counters in two different locations, but found that speeds were actually very consistent on Tulip Tree Drive. The data showed an average 85th percentile speed of 25 MPH and an average speed of 20 MPH. The 85th percentile speed is the speed at which 85% of vehicles are driving at or under and is most commonly used for purposes of setting a speed limit. So, the large majority are travelling at/under the currently posted speed limit. We will typically see that 85% speed be in the 22-30 MPH range for a neighborhood street, so this is well within that area.
Looking at the data a little deeper, we noted only 4 vehicles travelling over 40 MPH through the entire study duration. While ultimately we would love to say that 100% of drivers are travelling below the speed limit, even the best situations have outliers. What it does say is that even those drivers likely drove through the study area multiple times, and were typically in compliance with the posted speed limit.
At this time, we do not see any concerns with speeds on Tulip Tree Drive. My recommendation is to stay engaged as an HOA with the rest of the neighborhood to remind others that, even when running late, speeding out of the neighborhood is not the answer. It does appear that most are complying with that as it is, but a helpful reminder from time to time could go a long way.
Please let Sgt. Pagel or myself know if you have any additional questions.
HOA Reply:
Thank you so much for monitoring and sharing this information with us. It is very helpful and useful information. Just a couple of questions. Can you share with us what time of day that the 4 vehicles were traveling over 40 MPH. (We have a few delivery drivers who seem to be traveling a little fast in the neighborhood and have a general idea of their delivery schedule.) Also, do you have the total number of trips that were monitored by all the vehicles that passed over your counters in the neighborhood? As a clarification, the 85th percentile is telling us that 85% of the vehicles that passed your counters were driving 25MPH or less and that the remaining 15% were over the 25MPH with 4 of them exceeding 40MPH. As a point of reference, we would like to have an idea of the number of vehicles so that we understand how frequently the 25 MPH was exceeded and we can share this information with the neighborhood. We understand that 85% is probably a realistic number, but we anticipate that many of the residents would like to see the actual numbers used to calculate the results. Thanks again for your help and we appreciate any feedback you can provide in regards to our questions.
Reply from Andrew Rodewald:
Tony,
I am also copying in Ed Hamilton who reached out with similar questions so everyone is on the same chain. We do not share the raw data of these counts. The time of day was inconsistent for those vehicles travelling higher than 40, so it isn’t as simple as saying “have an officer sit there at 3:30”. My reasoning for stating that only 4 vehicles were travelling over 40 MPH was that at one point someone had stated that vehicles were regularly travelling over 50 MPH. I can tell you that 212 vehicles were counted by our system. Some of these will be duplicates because they were set so close to each other…it would make sense that someone living at the very back of the neighborhood drove over both on their way through. We would typically only put one set of counters in a location like this, but we wanted to see if there were any anomalies related to one location or another. Other than the volumes, speeds were fairly consistent.
The 85th percentile speed is a statistical measure used in the traffic engineering world that helps identify what speed the majority of drivers are travelling. I have been doing speed studies in Noblesville for over 20 years and don’t think I have seen a neighborhood yet that had 100% of cars in a particular study going under the speed limit.
This is not an uncommon situation that we see. Often speeds “from the front porch” seem much higher that what they are in reality. I can understand the concerns with having children around. From the numbers you stated, I would guess a pretty large percentage of the homes in the neighborhood have some amount of children. The drivers in those houses are probably pretty cognizant of speed. Even in the best cases, someone is running late for school, or work, or practice and takes off quicker than they should. That isn’t to excuse it, but that is the human nature aspect of driving that is difficult to overcome. The education aspect of this is more critical in these scenarios than roadway geometry or police enforcement. I would again continue to remind your neighbors that they’ve chosen to live in a neighborhood that does have a lot of children running around, and they aren’t always as mindful of their surroundings. Again, I think overall they are doing very well. You have relatively few outliers that need reminders.
If there are specific questions that were brought up at the meeting that I haven’t answered, please let me know.