Hi Daniel, 1st: thank you for the videos. CBT is insane. 2nd: equation on page 264 for density says that k= n/l.... shouldn't spacing be in the numerator?? thank you in advance for the clarification.
The equation (at 1:29 in the video also) is correct for density. The units end up as vehicles per mile, which are the units we need for density. At 3:33, I provide an example that introduces spacing, which has an inverse relationship with density. For instance, very small spacing results in a high density and large spacing results in low density.
@@oleopathic In my opinion, this is an important relationship and I think it just falls under the following NCEES statement: "The PE Civil Reference Handbook does not contain all the information required to answer every question on the exam. Theories, conversions, formulas, and definitions that examinees are expected to know have not been included."
Thank you for your video! 🤩 I am currently doing a science project in my highschool, with the topic of traffic signal timing, so it's really helpful! Uhmmmmm, but I have some inquiries that I would be very grateful if you can answer for me! 😢 Firstly, regarding how to actually count the traffic flow, as the papers I have been reading don't really mention it... Do we just count the flow during peak hour (because the greenwave common cycle uses the longest cycle so I guess we should use the peak hour for calculating the flow) or we calculate it at different time periods in a day and use the average figure (as I have seen how most figures of traffic flow on newspaper - not the scientific ones - are counted)? I need to use the figure for Webster's formula for the optimized cycle time (1957) and Hoàng Văn Trường et al (2022)... Secondly, can I use the designed saturated flow written in the road design for the formula? I am kinda perplexed by this since the intersection I am studying and the formula I use (Hoàng Văn Trường et al, 2022) are for mixed traffic, while the design use the PCE unit, and I have no statistic regarding the percentage of each kind of vehicles. Lastly, sometimes I get time cycle results that are negative, is there any explanation for this, if you do not mind?
I'm glad to hear that this information is helpful for you. I'll try my best to help you. This seems like a fairly advanced project - would you be open to some suggestions that might simplify your project? Most of our analysis is based on the peak 15 minutes within the peak hour (see QEM videos linked below for how that process occurs - several examples are linked), so I would recommend counting traffic by movement in 15-minute increments. The highway capacity manual can help convert vehicles to PCEs - for a high school class and assuming the grades of the road aren't steep, I think using a factor of 2 would be reasonable (i.e., each truck is the equivalent of 2 passenger vehicles). If your project can be adjusted/simplified, my recommendation would be to do a saturation flow rate study at the intersection and then use that value as a capacity to complete the QEM on the intersection. Saturation Flow Rate: ruclips.net/video/sUXr9j9mbw8/видео.html ruclips.net/video/pRVxB3mqHrA/видео.html Quick Estimation Method (QEM) - Critical Lane Analysis ruclips.net/video/Pgd4fraeEsM/видео.html ruclips.net/video/_p-rkbCGOPY/видео.html ruclips.net/video/woQXRuiU6zg/видео.html ruclips.net/video/ph5yp6ATd5g/видео.html ruclips.net/video/BI7Fx1hfIFw/видео.html
@@FindleyDanielHi, sorry for replying too late! I intended to get the result and respond in one time! Thanks to your helpful videos, I found a way to gather the necessary data, then participated in the contest and get a second prize! Although there are many other steps to do so as to finalize the project (fixing the codes and stuff), the result was really out of my expectation (probably because the police in my place still does not have a program assisting them in managing traffic signal and still uses manual methods). Hope you have a happy (Lunar) New Year! 😊🎉
In my opinion, this is an important relationship and I think it just falls under the following NCEES statement: "The PE Civil Reference Handbook does not contain all the information required to answer every question on the exam. Theories, conversions, formulas, and definitions that examinees are expected to know have not been included."
![Speed / Density / Flow Relationships | NCEES Civil Engineering PE Exam [Section 5.1.1.4; 5.1.2]](http://i.ytimg.com/vi/DmrmtYLabrI/mqdefault.jpg)
![Speed / Density / Flow Relationships | NCEES Civil Engineering PE Exam [Section 5.1.1.4; 5.1.2]](/img/tr.png)
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
![Space Mean Speed | NCEES Civil Engineering PE Exam [Section 5.1.1.2]](/img/1.gif)
Hi Daniel, 1st: thank you for the videos. CBT is insane. 2nd: equation on page 264 for density says that k= n/l.... shouldn't spacing be in the numerator?? thank you in advance for the clarification.
The equation (at 1:29 in the video also) is correct for density. The units end up as vehicles per mile, which are the units we need for density.
At 3:33, I provide an example that introduces spacing, which has an inverse relationship with density. For instance, very small spacing results in a high density and large spacing results in low density.
@@FindleyDaniel S = 1/k. yet, is this in the ncees hb 1.1? if so, which page?
@@oleopathic In my opinion, this is an important relationship and I think it just falls under the following NCEES statement: "The PE Civil Reference Handbook does not contain all the information required to answer every question on the exam. Theories, conversions, formulas, and definitions that examinees are expected to know have not been included."
@@FindleyDaniel Thank you for reply.
Why is CBT insane? Are you comparing it with the old pen/paper ?
Thank you for your video! 🤩
I am currently doing a science project in my highschool, with the topic of traffic signal timing, so it's really helpful!
Uhmmmmm, but I have some inquiries that I would be very grateful if you can answer for me! 😢
Firstly, regarding how to actually count the traffic flow, as the papers I have been reading don't really mention it... Do we just count the flow during peak hour (because the greenwave common cycle uses the longest cycle so I guess we should use the peak hour for calculating the flow) or we calculate it at different time periods in a day and use the average figure (as I have seen how most figures of traffic flow on newspaper - not the scientific ones - are counted)? I need to use the figure for Webster's formula for the optimized cycle time (1957) and Hoàng Văn Trường et al (2022)...
Secondly, can I use the designed saturated flow written in the road design for the formula? I am kinda perplexed by this since the intersection I am studying and the formula I use (Hoàng Văn Trường et al, 2022) are for mixed traffic, while the design use the PCE unit, and I have no statistic regarding the percentage of each kind of vehicles.
Lastly, sometimes I get time cycle results that are negative, is there any explanation for this, if you do not mind?
I'm glad to hear that this information is helpful for you. I'll try my best to help you. This seems like a fairly advanced project - would you be open to some suggestions that might simplify your project?
Most of our analysis is based on the peak 15 minutes within the peak hour (see QEM videos linked below for how that process occurs - several examples are linked), so I would recommend counting traffic by movement in 15-minute increments. The highway capacity manual can help convert vehicles to PCEs - for a high school class and assuming the grades of the road aren't steep, I think using a factor of 2 would be reasonable (i.e., each truck is the equivalent of 2 passenger vehicles). If your project can be adjusted/simplified, my recommendation would be to do a saturation flow rate study at the intersection and then use that value as a capacity to complete the QEM on the intersection.
Saturation Flow Rate:
ruclips.net/video/sUXr9j9mbw8/видео.html
ruclips.net/video/pRVxB3mqHrA/видео.html
Quick Estimation Method (QEM) - Critical Lane Analysis
ruclips.net/video/Pgd4fraeEsM/видео.html
ruclips.net/video/_p-rkbCGOPY/видео.html
ruclips.net/video/woQXRuiU6zg/видео.html
ruclips.net/video/ph5yp6ATd5g/видео.html
ruclips.net/video/BI7Fx1hfIFw/видео.html
@@FindleyDanielHi, sorry for replying too late! I intended to get the result and respond in one time!
Thanks to your helpful videos, I found a way to gather the necessary data, then participated in the contest and get a second prize!
Although there are many other steps to do so as to finalize the project (fixing the codes and stuff), the result was really out of my expectation (probably because the police in my place still does not have a program assisting them in managing traffic signal and still uses manual methods).
Hope you have a happy (Lunar) New Year! 😊🎉
Fantastic,@@Fisthier3! Good job!
@@FindleyDaniel Yes, it's thanks to the topic! And thank you very much, again! 🥰🥰🥰
ncees hb 1.1, pages 264, 265.
but where to find the eqn which shows relationship between spacing & density ?
In my opinion, this is an important relationship and I think it just falls under the following NCEES statement: "The PE Civil Reference Handbook does not contain all the information required to answer every question on the exam. Theories, conversions, formulas, and definitions that examinees are expected to know have not been included."
@@FindleyDaniel Thank you.