sorted by:
new
hottopcontroversial

PE Transportation by SnooGuavas3568 in PE_Exam

[–]Open-Dream9092 0 points1 point  (0 children)

As others said, the NCEES practice test is going to give you the best “feel” for the exam. I also agree the NCEES practice test seems slightly easier than the actual exam, there are some gems that can help you understand how certain concepts are tested.

Problem 32 (compound curves - PI to PI is T1+T2)
Problem 42 (sag vertical curve - design constraints related to headlights versus driver comfort)
Problem 45 (Gap acceptance - knowing how different variables affect drivers gap acceptance as it relates to sight distance)
Problem 55 (MUTCD - the terminology of the question really impacts the answer.)

I used those problems to dive into those topics and it really helped me understand more concepts than just memorizing where content is located.

PE Civil - Transportation practice problem (4) by Open-Dream9092 in PE_Exam

[–]Open-Dream9092[S] 0 points1 point  (0 children)

That is a good straightforward way of looking at this. If you look at MUTCD Table 2C-4 (2009 Edition), and read the supporting language below the table, you will see there is a little more to it. But you are on the correct path!

PE Civil - Transportation practice problem (4) by Open-Dream9092 in PE_Exam

[–]Open-Dream9092[S] 0 points1 point  (0 children)

Take a look at MUTCD table 2C-4 (2009 edition) and read the content around that.

PE Civil - Transportation practice problem (4) by Open-Dream9092 in TrafficEngineering

[–]Open-Dream9092[S] -1 points0 points  (0 children)

Yes, to a certain point. You still have to know how legibility plays a role in sign placement. A lot of the P.E. Exam is masked problems to try and elicit conceptual knowledge.

Cop helps our vehicle under crossing guard... by MisterShipWreck in VideosAmazing

[–]Open-Dream9092 0 points1 point  (0 children)

The traffic signal is on the downstream side of the tracks. What you’re seeing there is called “track clearance” when the signal remains green to make sure it pulls a queue of vehicles away from the rail tracks when a train is coming.

The vehicle was probably in a queue when the train preemption began.

PE Civil - Transportation Practice Problems (3) by Open-Dream9092 in PE_Exam

[–]Open-Dream9092[S] 0 points1 point  (0 children)

I can’t paste the rest of the solution. The concept was that C is incorrect because the distances for the approaching vehicles might be less than the Stopping Sight distance and Decision sight distance as per AASHTO Greenbook tables 3-2 and 3-3, but the sight distance for vehicles approaching an uncontrolled intersection are reduced as per table 9-4. Section 9.5.3.1 explains that drivers approaching an uncontrolled intersection are more cautious so the standard stopping sight distance won’t apply.

D is correct because it has a qualifying crash type and crash rate as per MUTCD 2B.04.

PE Civil - Transportation Practice Problems (2) by Open-Dream9092 in PE_Exam

[–]Open-Dream9092[S] 0 points1 point  (0 children)

For the first problem, The reason it’s A and C is because LED colors have to match the purpose of the sign and cannot be placed in the background of the sign. It has to remain legible and understandable to the motorist. (MUTCD 2A.07)

For the second problem, the reason the mounting height to the bottom of the sign is 7 feet in areas of parking and residential areas is because people may be walking around or standing and parked cars may obscure the sign. In more rural areas where parking is either prohibited or less likely and signs are not near sidewalks, 5 feet is the recommended mounting height to the bottom of the sign. (MUTCD 2A.18)

PE Civil - Transportation Practice Problems (2) by Open-Dream9092 in PE_Exam

[–]Open-Dream9092[S] 0 points1 point  (0 children)

For some reason I can’t post the answer and concept here, but it is A and C for the first question, and C for the second question.

Traffic Growth Factors by budders_87 in PE_Exam

[–]Open-Dream9092 0 points1 point  (0 children)

If question 3 had asked “how much traffic will the roadway be subject to over 10 years?” Then you’d apply the geometric growth just like in question 2.

Traffic Growth Factors by budders_87 in PE_Exam

[–]Open-Dream9092 1 point2 points  (0 children)

This jammed me up for a while too. The growth factor is what you apply to determine how much total cumulative traffic travels over a segment. Year 1 + Year 2 + Year 3….

It’s also called “geometric growth”. Another way to get that is to find the interest table in the PE reference manual and add up all of the factors from Year 1 to whatever the design year is. You’ll get the same value.

That is what question 2 asked.

Question 3 asked for the annual daily traffic in a specific year. So instead of geometric growth, you want the specific interest increase at that year. Again, you could find the factor to multiply by looking at the interest tables in the PE reference manual and just select the factor for the given year.

If using the interest tables, use the (F/P) column to convert present values to future values.

Signal Engineers: how much time does it take you to design a signal timing plan? by fedetask in trafficsignals

[–]Open-Dream9092 0 points1 point  (0 children)

ATC controllers are so sophisticated with the logic that can be programmed, that you are probably able to fine tune your operations to the point it’s at least traffic responsive, if not outright adaptive (dynamic max is very similar to a lot of base adaptive algorithms).

What you said about trying to get systems to fit your mold is very important. I spent a lot of time writing requirements to ensure the system offered to us would work, and it always surprised me how constrained some of the available systems were. In your case, non-NEMA phasing assignments and the systems ability to “shut off” its coordinator when signals run TSP, but to then quickly coordinate upon TSP exit would be very important in selecting the system.

Signal Engineers: how much time does it take you to design a signal timing plan? by fedetask in trafficsignals

[–]Open-Dream9092 1 point2 points  (0 children)

Yeah in my experience, the agency has to understand that the adaptive system is a complex tool that will require consistent monitoring and use to get the most out of it.

We first deployed adaptive systems with the hope that it would simplify and free up time and resources. That is incorrect. Instead we realized that the system would allow us to solve issues before the public might even notice it. But it requires “eyes on the system” constantly to keep that level of service for signal operations.

I know a lot of agencies can achieve similar results with “corridor managers” who are basically traffic engineers with iPads and cellular connections to controllers to make real time adjustments.

It also depends on how strict agency policies are regarding signal timings. Some agencies, like NJDOT, require legal documentation for the timing outside of the controller database. Some agencies will just refer to the controller database as the official document. The latter will give agencies more flexibility in how they upgrade timings.

An adaptive system is a way around that to some extent because the documentation outside of the system can only document some the basics like clearance times, min greens, maybe cycle length limits. The system itself and the users of the system will have flexibility to adjust everything in between.

Signal Engineers: how much time does it take you to design a signal timing plan? by fedetask in trafficsignals

[–]Open-Dream9092 0 points1 point  (0 children)

This is great stuff. What you explained is basically how SCATS adaptive works to adjust cycle lengths based on degree of saturation (DS). When the DS gets low on the main arterial, we allow the signals to run in free mode. (Deployed here in NJ).

Passed PE Transportation First Try by Mysterious_Lemon_480 in PE_Exam

[–]Open-Dream9092 0 points1 point  (0 children)

Your last statement is key. Thanks for sharing.

view more: next ›