Typical SectionsAll graphics taken from Ch 3 of HDM

CTC 440

Objectives

Know what a typical section is and what may be included in a typical section

Typical Sections

Show the physical shape and highway elements to be used when the project is constructed

Typical sections are generally included in a set of design plans

Several sections may be needed to describe a project

Typical Elements Number and width of lanes/shoulders Thickness of pavement layers Item #’s Payment limits Cut/fill slopes Ditch/gutter/curb/sidewalk locations

Control Lines Show how the typical section is

located w/ respect to horizontal/vertical control

HCL-horizontal control line TGL-theoretical grade line POR-point of rotation

Lane Width Show typical lane widths

Cross slopes & superelevation

Show typical pavt cross slope Show superelevated sections

Pavement Sections

Show pavement materials Show thickness of various layers

Superpave

New Superpave (from 1999) Old design was the Marshall mix Superpave more complicated

(refer to HDM Ch 3 and Pavement Design Manual)

Shoulders Shoulder width/cross slope Rollover limitations Shoulder thickness/materials

Conventional (being phased out) ESAL (full-depth

Shoulder break (0.7 m) Guide rail placement Lateral Support to the shoulder

Delineation ARD-Audible roadway delineators

Clear Zones

Distance from edge of traveled way to an actual obstacle or potential hazard.

If FO are to be removed typical sections should show clear zone

If not practical to provide a reasonable clear zone, a barrier system should be provided

Barriers

Guide Rail Box beam Corrugated Cable

Concrete Barriers

Medians-width and treatment

Curbs

Type Non-mountable Mountable Traversable Combination curb-gutter Asphalt Stone

Gutters

Collect runoff Use flattened and widened section

for drives

Sidewalks

Set back as far as practicable (snow storage, pedestrian space)

Thickness (100mm or 150mm@ drives)

Materials Concrete Asphalt (short-term) Bricks or pavers (historical/aesthetic)

Embankment (fill) slopes

For maintenance and safety--should be flat as possible

1:3 max w/o guide rail 1:2 w/ guide rail

Ditches Show ditch dimensions/slopes Should provide traversable ditches

(1:6 down; 1.2m-width; 1:4 out) w/in clear zone

If can’t provide traversable ditches consider guide rail (or use professional judgement—guide rails in themselves can potentially be hazardous)

ROW Width

Sometimes shown on typical sections

Modifications needing Typical Sections

Overlays Cracking & Seating Rubblizing Lane Additions and Widening Miscellaneous

Edge drains Adding curbs to existing pavts.