VEHICULAR IMPACT GUARDRAILS - TYPE A&B TERMINALS - Standard Detail

Sep 20, 2026

Uploaded by Aurelia

Standard detailing for vehicular impact guardrails covering TYPE A&B terminals and crash cushion transitions. Specifies scales and plan/side elevation presentation, and provides engineering notes on modification approval, clear zone assessment, Breakaway Cable Terminal (BCT) hot-dip galvanizing, hole drilling sequence, bolt snug-tightening, and concrete strength requirements (C28/35). Includes installation guidance for mounting height and drill-hole datum, references to AS/NZ 3845:1999 and terminal selection by design speed (≤70 km/h for Type A; >70 km/h for Type B/crash cushion), plus visibility and safety considerations.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

NOTES

Design and installation requirements

Terminal selection by speed and safety requirements

REVISION # DRAWING TITLE DRAWING NO. VEHICULAR IMPACT GUARDRAILS-TYPE A&B TERMINALSLTA/SDRE14/6/VIG1BVEHICULAR IMPACT GUARDRAILS-CRASH CUSHIONLTA/SDRE14/6/VIG2ACONCRETE BARRIER AT CENTER MEDIANLTA/SDRE14/6/VIG3AARRANGEMENT AND CONNECTION DETAILS OFVEHICULAR IMPACT GUARDRAILSLTA/SDRE14/6/VIG4AVEHICULAR IMPACT GUARDRAILS-THRIE-BEAM TRANSITIONLTA/SDRE14/6/VIG5BDOUBLE SIDED VEHICULAR IMPACT GUARDRAILLTA/SDRE14/6/VIG6AGUARDRAILS IN FRONT OF COLUMN-WITHOUT ADJOININGVEHICULAR IMPACT GUARDRAILSLTA/SDRE14/6/VIG7CGUARDRAILS IN FRONT OF COLUMN-WITH ADJOININGVEHICULAR IMPACT GUARDRAILSLTA/SDRE14/6/VIG8 PLAN SCALE 1:100 # WEAKENING TREATMENT TYPEB-CABLE-ANCHORED TERMINAL SCALE 1:20 SCALE 1:50 | NOTES:
1.The agreement of the engineer shall be sought before modifications are made to
any part of the design.
2.The design engineer must consider each specific situation pertaining the available
clear zone and specify the appropriate treatment of terminal.
3.Breakaway Cable Terminal(BCT)assembly to be hot-dip galvanized(including nuts
bolts and washers).Holes to be drilled before galvanizing.
4.The first five posts in Breakaway Cable Terminals(BCT)shallbe timber except on
bridge approaches where steel posts have to be retained for 10m minimum the last
post of BCT can be steel.
5.Bolts to be snug-tightened.
6.All concrete shallbe C28/35 at 28 days strength,unless otherwise specified. | 7.Where the face of guard fence is erected within 1m behind the back of kerb,
the mounting height shall be measured from the adjacent road pavement
surface.However,the vertical position of the drilled holes in the timber
posts shall be measured from the ground surface.
8.For more details,refer to Australia/New Zealand Standard Road Safety
,
Barrier System AS/NZ 3845:1999.
9.Type A terminals shall be used for vehicular impact guardrail where design
speed limit is not more than 70km/h.
①⑩.Type B terminals or crash cushion shall be used for vehicular impact
guardrall where design speed limit is more than 70km/h.
11.Vehicular impact guardrail installed shall not block the view of motorist
exiting from side road at alltimes. | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | STANDARD DETAIL | Land Transport Authority | | | | | | | | | | | | | | | | | | | | | | | | | | VEHICULAR IMPACT
GUARDRAILS-
TYPE A&B TERMINALS | | | | | | | | | | | | | | | | | | | | | | | | | | | | REV.
DRAWING NO.
LTA/SDRE14/6NIG1
B | | | | | | | | | | | | | | | B□ | SEP 2017
OCT 2015
DATE | | | | | | | | A
REV. | | | DATE OF ISSUE
1st APR 2014 | SCALE
AS SHOWN | SHEET NO.
1 OF 2 | 6-1 # NOTES 1. The contractor shall engage the system manufacturer/manufacturercertified installer to propose the type of crash cushion and develop thedesign details including allnecessary on-site modifications to install thecrash cushion. 2. The system manufacturer /manufacturer certified installer shall consider thefollowing factors: A. The crash cushion is certified to meet the evaluation requirements ofNCHRP Reports 350(National Co-operative Highway Research Programme)or equlvalent for a non-gatlng termlnal,and ls approprlateto the operating or design speed limit of the main carriageway. B. A minimum length of 70m(for expressway)or 50m(for non-expressway) is provided for chevron-marking in front of the crash cushion. C. The wldth of the crash cushlon Is sufflclent to shleld the hazard at gorearea. D. The surrounding site features such as kerb,lamp post,roadside drains,junction boxes etc.have been adequately removed /treated to ensurethat the installation of the crash cushion and the safety barrier at thetransition section will not create any undue or secondary hazards.Thekerb behind the

FAQs

What approval is required before modifying the guardrail design?

The engineer’s approval must be sought before modifications are made to any part of the design.

How should Type A vs Type B terminals be selected by design speed?

Use Type A terminals when the design speed limit is not more than 70 km/h; use Type B terminals or crash cushions when the design speed limit is more than 70 km/h.

What are key installation and material requirements for the Breakaway Cable Terminal (BCT)?

BCT assemblies must be hot-dip galvanized (including nuts, bolts, and washers), with holes drilled before galvanizing, and bolts snug-tightened; concrete should be C28/35 at 28 days strength unless otherwise specified.

Sep 20, 2026

Uploaded by Aurelia