Macrodata Refinement

Anshum p -

This week, I reverted my focus back to numerical data in hopes of discovering more patterns and trends. I’m still figuring out Synchro, but that should be up and running in a few weeks’ time.

In more exciting news however, I’m beginning phase two of my project as it begins to overlap with phase 1. I will now be examining the best countermeasures to propose based on the data I have compiled, analyzed and mapped. In order to do this, I’ll be using a well known database in transportation engineering: CMF Clearinghouse

 

Here is a brief explanation of what this is exactly: 

CMF Clearinghouse is a huge set of real numbers, all ranging from 0 to infinity (theoretical). These numbers are called CMF’s ( Crash Modification Factors ). Each factor is tied to a countermeasure. As the word suggests, a countermeasure is a change made to a road system to potentially decrease crashes and congestion. This can be anything from a stop sign, new lane, wider lanes, roundabouts, etc. If the CMF factor is less than 1.0, then you know that the change will decrease crashes. If it’s above 1.0, then the change will increase crashes. 

One thing that is important to note is that these factors are calculated mostly based on empirical data. The team behind CMF Clearinghouse examines crash data before and after a certain change was implemented, and then uses those findings to calculate a factor. Additionally, they are able to come up with a math equation to represent their factor calculation: Here is an example of a formula that calculates the CMF after a change in lane width of a rural frontage road ( road used in parallel to a major highway to provide access to nearby buildings).

 

 

Tomorrow, I will be flying out of Sky Harbor Airport, which is great because I’ll get to see the current road traffic firsthand. I will talk about it in my next blog, which will be on March 24th( two week break ).


That’s it for now!

 

 

 

 

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Comments:

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    daniel_j
    Sounds like an exciting transition into phase two! I like how you are able to integrate empirical data with real-world countermeasures. Looking forward to seeing what insights CMF Clearinghouse brings to your analysis. Safe travels!
    March 11, 2025 at 3:34 pm - Reply
    Siddharth Patil
    I see what you are referencing in your title... That's funny. I'm excited to see how your project progresses!
    March 11, 2025 at 10:54 pm - Reply
    ryan_d
    Haha great reference! Are you planning to look at how many countermeasures could interact when implemented together?
    March 12, 2025 at 12:36 pm - Reply
    rowena_rahman
    The CMF Clearinghouse software looks really interesting! I've never done super heavy mathematical-based research before so I'm a bit curious about the methodology. What's the possible chance for error using this equation and how much data is based on aka what are your parameters for ensuring how accurate it is? Looking forward to your next post!
    March 13, 2025 at 1:45 pm - Reply
    Denise Baker
    Hi Anshum, it's great to see your progress documented here. I am glad you are enjoying Synchro as well and learning about traffic simulations too. I can help answer some of the questions I've seen here. For the CMF methodology - each factor has a scholarly article attached to it where its methodology is described. It varies a lot in terms of the conditions the data was collected and sample size. The clearinghouse, which is a national tool from FHWA (Federal Highway Administration), has a star rating system that rates the confidence of the results. Usually, we only use CMFs with star ratings of 4 or 5. It takes into account methodology, sample size, and other factors. It's also important to pay attention to the data collection context and type of crashes that it is applicable to. For multiple countermeasures - the recommended method to combine CMFs is to multiply them to get a combined factor. It is very common for multiple countermeasures to be applied at the same time. However, the more CMFs you multiply to get the combined factor, greater your error is. For that reason, we usually limit the number of countermeasures combined into the CMF to three. I am looking forward to catching up with this project!
    March 28, 2025 at 7:24 pm - Reply
    Anshum Patel
    Thanks Daniel!
    March 30, 2025 at 2:19 pm - Reply
    Anshum Patel
    Hi Ryan! I am currently looking into that yes.
    March 30, 2025 at 2:19 pm - Reply
    Anshum Patel
    Hi Ms. Rowena! My parameters for ensuring accuracy will msotly be based off the start rating of each CMF, which takes into account error mitigating factors
    March 30, 2025 at 2:21 pm - Reply
    Anshum Patel
    Thanks Sid!
    March 30, 2025 at 2:21 pm - Reply
    Anshum Patel
    Hi Denise! I appreciate the feedback, and look forward to catching up soon.
    March 30, 2025 at 2:22 pm - Reply

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