Question

1.Why are Trucks of concern for defining the LOS for basic freeway, multilane highway and weaving sections?

2. Discuss and identify the difference between ramp-weave and major weave segments.

Answer 1

A freeway is defined as a divided highway with full control traffic flow with two or more lanes for the traffic ,movement in each direction. Freeways provide uninterrupted traffic flow through road.

Weaving is defined as the crossing of two or more traffic streams while driving in the same general direction in a highway without the aid of traffic control devices.

Weaving segments are formed when a merge area is followed by a diverge area, or when an on-ramp followed by an off-ramp or the two are joined by an auxiliary lane.

a multi lane can be defined as a highway with at least two lanes for the exclusive use of traffic in each direction with no control but have signalized intersections (generally not less than 3KM ]

level of service or LOS is defined to represent reasonable ranges in the three critical flow variables: speed, density, and flow rate

• To determine percentage of heavy vehicles in rolling and mountainous terrain, if the proportion of other vehicles are not known all the heavy vehicles can be considered to be trucks for selecting passenger-car equivalents and computing the heavy-vehicle adjustment factor.
• weaving width is defined as the total number of lanes between the entry and exit including the auxiliary lane or the carriage way bet ween entry and exit, the heavy vehicles like truck gives maximum axle distances to design an all purpose width. which is an important factor in weaving segment design
• multi lane design is also governed by width of the lane, for which the trucks give a general design and maximum value.

ramp weave	major weave segments
Ramps are constructed to cross the pathways	no ramps are constructed for merging or diverging
for weaving analysis heavy vehicles percentage is considered	no vehicle percentage required

I T TI ----- (a) One-Sided Ramp-Weave

(b) One-Sided Major Weave