2/2008 GISC 6382 UT-Dallas Briggs 1 Geometric Networks in ArcGIS Sewer, water, roads, etc..
2+1 Roads, Geometric Design - nmfv.dk1-Roads-Geometric... · Federal Highway Research Institute,...
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Federal Highway Research Institute, Germany Dr.-Ing. Thomas Jährig 5 th Meeting of the Rural Roads Design Group in Copenhagen, 04/04/2014 2+1 Roads, Geometric Design Experiences from Germany
Transcript of 2+1 Roads, Geometric Design - nmfv.dk1-Roads-Geometric... · Federal Highway Research Institute,...
Federal Highway Research Institute, Germany
Dr.-Ing.
Thomas Jährig
5th Meeting of the Rural Roads Design Group in Copenhagen, 04/04/2014
2+1 Roads, Geometric Design
Experiences from Germany
Road Classification in Germany
Page 2
• Functional Relationship of the Road Network
Link function level + Category group = Road Category
EKL 1 = 2+1 road
• Road Design Guideline principle:
“standardization” and “recognizability”
– only a few road types (design classes) for motorways and rural roads
– as uniform as possible within the same design class
– noticeable difference to other design classes
– tight specifications for different road types (cross-sections, values and design elements, forms of junctions, etc.)
Page 3
Road Design Principle
Design Class 1
Rural Road Cross-Sections
Page 4
Design Class 2
Design Class 3 Design Class 4
0,500,505,00
road marking as the only recognizable road element
RAS-Q vs. RAL
Page 5
11,50
15,50
0,500,25 0,25
2,50 3,75 3,25 3,50 1,50
Design Class 1
2+1
Page 6
long distance traffic(40-160 km)
AADT:
up to 22.000 veh/d
by Prof. Weise, TU Dresden
2+1
Page 7
Principles of “2+1”
• continuous alternating passing lane
• 40% safe overtaking opportunities in each direction
• passing lane length 1.000 m to 2.000 m
• directions are separated by a median reserve (green colour)
• emergency lay-by’s in the one lane direction (each 1.000 m)
• along a longer distance
• AADT from ~12.000 veh/day up to ~22.000 veh/day
• only level free intersections
• restriction to motor vehicles
Alignment
• radii: ≥ 500 m
• slope:≤ 4 %
• crest: ≥ 8.000 m
• sag: ≥ 4.000 m
Road Safety on 2+1 roads
Page 8
2+1 road safety in general (Meewes, 1984; Brannolte, 1992; GDV, 2002; Weber, 2005)
• high level of safety
• lowest accident cost rate of all single carriageway roads
• low number of accidents (especially head-on crashes)
• most accidents in lateral direction while merging in front of the ghost island
Most accidents caused by:
• excessive speed
• bad weather conditions
• crossing animals (game)
• overtaking even if it is prohibited (rarely)
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7,50m 8,00m 8,50m 10,00 -
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width of the carriagewayIGS, 2010
1+1 2+1 2+2
• non-critical changeover (vehicles are not heading towards one another)
• critical changeover (vehicles in the middle lane are heading towards one another)
Changeovers - Marking and Signage
Page 9
short taper of only 10m by RAL 2012
by RAL 2012
• begin of a 2+1 Section
• end of a 2+1 section
Marking and Signage
Page 10
taper length 120 m
Changeover - Marking and Signage
Page 11
by Prof. Weise, TU Dresden
signs are showing the distance
to the next passing lane
by Prof. Weise, TU Dresden
“barrier effect” to reduce
driving over critical island
Changeover - Marking and Signage
Page 12
by Prof. Weise, TU Dresden
large arrow marking:
• indicates passing lane end
• better visibility
• supports correct driving behaviour
emergency lay-by
Page 13
by ivh, 2009
• only level free or grade separated junctions
– better road safety
– meet the standards for average travel time
Junction Design
Page 14
by ivh, 2009 by ivh, 2009
