Search results
Results from the WOW.Com Content Network
In the case of automobile traffic, the key consideration in braking performance is the user's reaction time. [6] Unlike the train case, the stopping distance is generally much shorter than the spotting distance. That means that the driver will be matching their speed to the vehicle in front before they reach it, eliminating the "brick-wall" effect.
Passenger car equivalent (PCE) or passenger car unit (PCU) is a metric used in transportation engineering to assess traffic-flow rate on a highway. [1]A passenger car equivalent is essentially the impact that a mode of transport has on traffic variables (such as headway, speed, density) compared to a single car.
An early traffic engineer Henry Barnes, who served as Commissioner of Traffic in many cities including Baltimore, Maryland and New York City, developed coordinated traffic signal timings, so that large amounts of traffic could be accommodated on major traffic arterials. Traffic signal timing is a very complex topic.
Geometric relations from the fundamental diagram can be used to calculate the density as well, given by the equation: k A = (k j w)/(v A +w) In the time-space diagram, the trajectories of the leading (top) and following (bottom) vehicle are separated by the distance δ and time τ. The spacing between vehicles at traffic state A can be found ...
The flow and capacity at which this point occurs is the optimum flow and optimum density, respectively. The flow density diagram is used to give the traffic condition of a roadway. With the traffic conditions, time-space diagrams can be created to give travel time, delay, and queue lengths of a road segment.
Stopping sight distance is one of several types of sight distance used in road design.It is a near worst-case distance a vehicle driver needs to be able to see in order to have room to stop before colliding with something in the roadway, such as a pedestrian in a crosswalk, a stopped vehicle, or road debris.
In transportation engineering, traffic flow is the study of interactions between travellers (including pedestrians, cyclists, drivers, and their vehicles) and infrastructure (including highways, signage, and traffic control devices), with the aim of understanding and developing an optimal transport network with efficient movement of traffic and minimal traffic congestion problems.
The GEH formula is useful in situations such as the following: [4] [5] [6] Comparing a set of traffic volumes from manual traffic counts with a set of volumes done at the same locations using automation (e.g. a pneumatic tube traffic counter is used to check the total entering volumes at an intersection to affirm the work done by technicians doing a manual count of the turn volumes).