Designers do not always understand what they are designing. Drawings go to drafters, who do not always understand what they are drawing. Plans go to Contractors, who may or may not recognize a error. There is a current class of managers who think that schedule and budget are more important than...
After graduation, I was interviewed by a number of private firms and eventually hired by a government agency that was expanding its construction program. I had wanted to do structural work, but was hired into a different discipline. When I said I did not have experience in that discipline, I was...
Not clear on the loop layout. Classic volume density relies on advance detection and not stopline loops. Regardless of the configuration, the following should hold. Since the loop is in not in an exclusive turn lane, it can't tell if the waiting cars want to go through or left. The 3s delay...
Synchro is a mathematical model. In most instances it provides a reasonable approximation of operations. Sometimes the analysis bears no resemblance to what is occurring in the real world. If the model is not accurate you have to make adjustments to the inputs. In this case it may be the...
In general I would consider a December count to represent something less than average conditions, but it depends on the location. For a site associated with commercial shopping areas a December count may represent a higher than average tally.
Failure at opening is a cause for concern and the...
I would consider extending the center lane lines to the edge of sidestreet to maximize storage and convert the center lane to back-to-back left turn lanes for this section. Minimal storage for the sidestreet and remaining pavement for the truck entrance.
Synchro is a mathematical model that approximates intersection operations and calculates delays and queues from a limited number of input values. The results are reasonably accurate for most conditions being analyzed. If the SimTraffic simulation associated with Sychro is run for a long enough...
I have never seen a "Warrant" for an exclusive pedestrian phase. Most discussion in the traffic literature has been general in nature with phrases such as "heavy" pedestrian traffic often present.
Pages 196-197 of the Signalized Intersections: Imformational Guide has a decent discussion of the...
The difference between the supplied truck graphic and that shown in the Standard Sign book is minor and does not interfere with the intended message. I would not call for replacement, but would notify the Contractor that any signs supplied in the future should not differ from those in the...
If you are interested in traffic engineering you shoulf pursue that interest until it no longer works for you. Traffic is usually more interesting than the other transportation fields and a knowledge of traffic engineering will make you a better (and more marketable) transportation engineer.
I...
Most signal plans will have a Phase Timing Chart showing the values to be set in the controller for the phase intervals utilized (minimum, extension, max, yellow,all red, etc.). The chart also shows the signal head display (G,Y,R)associated with each phase interval. The purpose of the Phase...
In general you only need to define which road has the right of way at an intersection, the junction of two roadways at grade. State Motor Vehicle Codes usually require driveway traffic to yield to all traffic including sidewalk traffic, making the stop sign unnecessary. Where the commercial...
I am very comfortable in using Synchro for analyzing signalized networks. I find it to be very reliable for that purpose. I am not familiar with the methodology Synchro utilizes to evaluate roundabout operations, so I am less likely to use it for that purpose.
From what I understand, each of...
Synchro will develop a coordination plan that minimizes delay in the corridor. How good it is depends on the work you put into the network or corridor you build. Synchro allows you to group adjacent signals together or break them into separate groups of signals.
You need to be aware not all...
From what I have read in published research over the past 20 years, Oakland County, Michigan has often been out in front in experimenting with newer technologies. The State of Maryland has also been active.
Are the signs being hit by passenger vehicles leaving the lane of travel or by large vehicles overtracking the island on turns?
If overtracking vehicles are the culprit you could try posting the sign slightly farther from the nose.
Snow plows take down a number of these signs in our area, so...
Thank you for the clarification. It appears the parties involved have different undestandings of what the word "paved" means.
The 2nd edition of Croney & Croney's The Design and Performance of Road Pavements (McGraw Hill 1991) defines "pavement" as follows:
"The pavement is the structure which...
It is my understanding that Bituminous Surface Treatments such as "chip seals" are used to extend the life of an existing pavement by sealing cracks and providing an improved wearing surface. I would not consider it a structural element of the "pavement", which is wht is under the BST.
