2005 survey of free speeds

8/3/2019 2005 Survey of Free Speeds

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2005 Survey of

Free Speeds

(Urban and Rural)

National Roads AuthorityAn tdaras um Bithre Nisinta


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2005 Survey ofFree Speeds

(Urban and Rural)

Published by:NATIONAL ROADS AUTHORITY RS 470

St Martins HouseWaterloo RoadDublin 4, IRELAND


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Acknowledgments

This report follows on from the 2002 and 2003 surveys of Free Speeds (Urbanand Rural) and Seat-belt Wearing Rates published by the NRA and similarsurveys undertaken by ARUP Consulting Engineers and PavementManagement Services Ltd on behalf of the NRA in 1999.

The author would like to extend particular thanks to: Robert dArcy, AnneBlake, Cynthia Tobin and Irene OShea of the NRA Road Accident Bureau;Anne Church and Dermot McCormack; Eileen Gallagher of the NationalRoads Regional Design Office, Donegal; Enda Waters of the National RoadsRegional Design Office, Tramore; Noel Kissane of the National Roads DesignOffice, Kerry and Paul Crowe of Limerick County Council.


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Table of ContentsPage

Acknowledgments............................................................................................2 Table of Contents.............................................................................................3Executive Summary.........................................................................................5Chapter 1 Free speeds surveys - background ................................................. 7

1.1 Metrication.....................................................................................................7

1.2 Background....................................................................................................7

1.3 The principal findings on free speeds on rural roads in 2003:.......................8

1.4 The principal findings on free speeds on urban roads in 2003: .....................8

Chapter 2 Summary of 2005 survey findings ..............................................9Chapter 3 Free speeds (urban) survey, 2005............................................11

3.1 Free speeds (urban) survey methodology ....................................................11

3.2 Free speeds (urban) survey results ...............................................................12

Table 3.1 Percentage exceeding speed limits on urban roads, 2005................12

Table 3.2 Distribution of free speeds (%) on urban roads, 2005. ....................13Table 3.3 Free speed (urban): Comparison of results for 2005 and 2003........13

Chapter 4 Free speeds (rural) survey, 2005..............................................144.1 Free speeds (rural) survey methodology......................................................14

4.2 Free speeds (rural) survey results ................................................................14

Table 4.1 Percentage exceeding speed limits on rural roads, 2005. ................15

Table 4.2 Distribution of free speeds (%) on rural roads, 2005.......................16

Table 4.3 Free speed percentiles on rural roads, 2005.....................................17

Table 4.4 Free speed (rural): Comparison of results for 2005 and 2003. .......18

Appendix 1: Vehicle classes surveyed in free speed surveys...................19Appendix 2: Free speed (urban) survey procedures.................................20

Appendix 3: Sample free speed survey sheet...........................................21Appendix 4: Free speed (rural) survey procedures...................................22Appendix 5: Free speeds (urban) survey locations...................................23

Table A5.1 Urban national 50 km/h sign.....................................................23

Table A5.2 Urban arterial 60 km/h speed limit zone...................................23

Table A5.3 Urban arterial 50 km/h speed limit zone...................................24

Table A5.4 Urban residential 50 km/h zone .................................................24

Appendix 6: Free speeds (rural) survey locations.....................................25Table A6.1 Motorway.....................................................................................25

Table A6.2 Dual carriageway .........................................................................25

Table A6.3 National Primary (2-Lane) ...........................................................26

Table A6.4 National Secondary (2-Lane).......................................................26Table A6.5 Regional road (2-Lane) ................................................................27

Table A6.6 County road (2-Lane)...................................................................27

Appendix 7: Free speeds (urban) survey results by location, 2005. .........28Table A7.1 Urban arterial 50 km/h zone cars ...........................................28

Table A7.2 Urban arterial 60 km/h zone cars ...........................................28

Table A7.3 Urban national 50 km/h sign - articulated vehicles ..................29

Table A7.4 Urban national 50 km/h sign cars ..........................................29

Table A7.5 Urban national - 50 km/h sign - rigid vehicles ............................30

Table A7.6 Urban residential 50 km/h zone cars......................................30

Appendix 8: Free speeds (rural) survey results by location, 2005. ........... 31Table A8.1 Motorway - articulated vehicles...................................................31

Table A8.2 Motorway - cars ...........................................................................31


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Table A8.3 Motorway - rigid vehicles ............................................................32

Table A8.4 Dual carriageway - articulated vehicles ......................................32

Table A8.5 Dual carriageway - cars ...............................................................33

Table A8.6 Dual carriageway - rigid vehicles ...............................................33

Table A8.7 2-Lane national primary - articulated vehicles ............................34

Table A8.8 2-Lane national primary cars ....................................................34Table A8.9 2-Lane national primary - rigid vehicles......................................35

Table A8.10 2-Lane national secondary - articulated vehicles.........................35

Table A8.11 2-Lane national secondary cars.................................................36

Table A8.12 2-Lane national secondary - rigid vehicles ..................................36

Table A8.13 Regional road (2-Lane) articulated vehicles .............................37

Table A8.14 Regional road (2-Lane) cars......................................................37

Table A8.15 Regional road (2-Lane) -rigid vehicles ........................................38

Table A8.16 County road (2-Lane) - cars .........................................................38


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Executive Summary

This report describes the results of surveys undertaken by the National RoadsAuthority in June - August 2005 in relation to free speeds on Irish roads. Theprincipal findings are presented for:

free speeds in urban areas, and

free speeds in rural areas.

Free speedsFree speed is defined as the speed at which the drivers choose to travel whenunconstrained by either road geometry (e.g. sharp bends), weather conditions(e.g. rain) or traffic conditions (e.g. congestion). The rural and urban speedsurveys measure free speeds only; and therefore the average speedcomputed from these surveys would considerably overestimate the average

speed on the network as constrained vehicles tend to travel at lower speeds.

Free Speed Survey in Rural Areas

Surveys were undertaken on:

motorways;

dual carriageways;

national primary (2-lane) roads;

national secondary (2-lane) roads;

regional, and county roads.

Principal results free speeds in rural areas

The 2005 free speeds (rural) survey generally showed increased free speedscompared to 2003 on rural roads. Average observed car free speedsincreased on motorways, dual carriageways, national primaries and onregional roads.

The reduction in speed limits applicable to cars on regional and county roads,

coinciding with the introduction of metric speed limits on 20 January, 2005,combined with changes in levels of speeding, has resulted in sharplyincreased transgression rates on these road types. In 2003, the proportion offree-speeding cars transgressing the speed limit was estimated to be 8 percent for regional roads and 10 per cent for county roads. In 2005, after theadoption of new (lower) speed limits on these road types, non-compliancerates increased to 63 per cent and 37 per cent respectively.

The average free speeds of articulated and rigid vehicles increased on dualcarriageways and regional roads but decreased on national secondary roads.Non-compliance rates for these vehicle types on rural roads remain high,

varying between 45 94 per cent for articulated vehicles and between 30-88per cent for rigid vehicles.


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Free speeds in urban areas

This survey measures free speeds only and does not analyse changes toaverage speeds on the network.

Speed measurements were taken on the following road types: urban arterial(in 50 km/h and 60 km/h zones), urban national (incoming traffic at 50 km/hsigns) and urban residential (in 50 km/h zones).

Results of free speed surveys are presented for four different vehicle classes:articulated vehicles, single deck buses, rigid vehicles and cars. Owing to therelatively small sample size, results for articulated vehicles, single deck busesand rigid vehicles are presented for urban national roads only.

Principal results free speeds in urban areas

Free speeds were generally found to have fallen in urban areas over theperiod 2003 2005, with the notable exception of car free speeds on urbanarterial roads within 50 km/h zones. Average car free speeds fell by anestimated 2 km/h on urban residential roads and on urban arterial roads within60 km/h speed limits. Average car free speeds fell by 4 km/h on urbannational roads at the 50 km/h speed limit sign.

The average observed free speed for single deck buses on urban nationalroads at the 50 km/h speed limit sign, based on a limited sample, is estimated

at 56 km/h.

The average recorded free speed of an articulated vehicle entering the 50km/h speed limit zone on urban national roads is 61 km/h, while for rigidvehicles the figure is 58 km/h. An estimated 89 per cent of articulated vehiclesand 80 per cent of rigid vehicles exceeded the designated speed limit onentering such roads.


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Chapter 1 Free speeds surveys - background

1.1 Metrication

On the 20 January, 2005, the measurement of speed limits on Irish roads waschanged from miles per hour (mph) to kilometres per hour (km/h). In addition,there were significant changes to speed limits on certain roads and alterationsto vehicle speed limits.

The speed limit on motorways changed from 70 mph to 120km/h (equivalentto 75 mph); on dual carriageways and national roads from 60 mph to 100km/h (62 mph); on inter-urban regional and county roads from 60 mph to 80km/h (50 mph).

In terms of urban areas, the 30 mph speed limit was changed to 50 km/h(equivalent to 31 mph), and the 40 mph speed limit to 60 km/h (37 mph).

In addition to these carriageway type specific speed limit changes, vehicle-specific speed limits were also changed to km/h. The speed limit applying tosingle-deck buses, towing vehicles and trucks (over 3,500 kg gross weight)was changed from 50 mph to 80 km/h, while the speed limit applicable todouble deck buses went from 40 mph to 65 km/h.

Following the metrication of speed limits, present survey average speedresults in this publication are in km/h. For the purposes of the 2005 survey,

compliance was measured in respect of the new (post-metrication) speedlimits. For comparative purposes, a number of tables are presented showingpreviously reported compliance with speed limits (principally from the 2003survey); these figures show compliance with previous applicable speed limits,i.e mph.

There is therefore a significant difference in the basis used to assesscompliance: those for 2005 present compliance with (new) km/h speed limits,those for the 2003 with (old) mph speed limits. However, viewed in anotherway the compliance numbers are strictly comparable: they both measurecompliance with the speed limits which applied in law at the time of the

respective surveys. The reader is asked to bear in mind changes to the speedlimit regulations when comparing compliance figures recorded in surveysconducted over different time periods.

1.2 Background

The Government Road Safety Strategy requires the National Roads Authority(NRA) to carry out national surveys in relation to seat-belt wearing and trafficspeeds. Survey results are used by the High Level Group on Road Safety tomonitor trends, determine the effectiveness of safety initiatives and to informthe on-going review of policy in relation to road safety.


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In 1999 the NRA commissioned ARUP Consulting Engineers and PMSPavement Management Services to undertake separate surveys of freespeeds in rural areas and in urban areas and also seat-belt wearing rates.Three reports were subsequently published (Free Speeds on Rural Roads

1999; Free Speeds on Urban Roads 1999 and Seat-belt Wearing Rates1999).

The NRAs 2002 and 2003 Surveys of Free Speeds (Urban and Rural) andSeat-belt Wearing Rates were based on the methodology outlined in the 1999reports. Sections 1.1 and 1.2 below outline some of the principal results fromthe 2003 speeds survey.

1.3 The principal findings on free speeds on rural roads in 2003:

There were significant improvements in the proportion of cars complying with

speed limits on dual carriageways and two-lane national primary roads in2003, with the proportion of free-speeding cars breaking the posted limitfalling from 43 per cent in 2002 to 29 per cent in 2003 on dual carriagewaysand from 44 per cent to 30 per cent on national primary roads over the sameperiod.

Average car free speed was 109 km/h on motorways, 96 km/h on dualcarriageways, 94 km/h on two-lane national primaries, 85 km/h on two-lanenational secondaries and 84 km/h and 75 km/h on regional and county roadsrespectively.

1.4 The principal findings on free speeds on urban roads in 2003:

The proportion of cars exceeding the speed limit on urban arterial roads (in 30mph zones) fell by 13 percentage points to 86 per cent in 2003.

There was a significant fall in the percentage of cars exceeding the 30 mphspeed limit in urban residential areas from 61 per cent in 2002 to 36 per centin 2003.

Slight increases were noted in average free speeds on urban national roads.


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Chapter 2 Summary of 2005 survey findings

2.1 Free speeds (urban)

The free speeds (urban) 2005 survey measured the speeds of vehiclesunconstrained by traffic, weather conditions or road geometry on urban roadswhere it was possible to travel faster than the speed limit.

With one notable exception [car free speeds on urban arterial roads in 50km/h zones], free speeds were found to have fallen in urban areas over theperiod 2003 2005. Average car free speeds fell by an estimated two km/h onboth urban residential roads and on urban arterial roads within 60 km/h speedlimits. Average car free speeds fell by four km/h on urban national roads at the50 km/h speed limit sign.

The average observed free speed for single deck buses on urban nationalroads at the 50 km/h speed limit sign, based on a limited sample, is estimatedat 56 km/h.

The average free speeds of goods vehicles entering 50 km/h speed zones onurban national roads decreased since the 2003 survey. In 2005 the averagespeed of an articulated vehicle entering such a zone was 61 km/h, a reductionof two km/h, while the respective figure for rigid vehicles fell by eight km/h to58 km/h. Nevertheless, a high proportion of goods vehicles were still found tohave been exceeding the speed limit.

Free speed (urban): Comparison of results for 2005 and 2003.2005

ExceedingSpeed Limit

(%)

2003Exceeding

Speed Limit(%)*

2005average

FreeSpeed (km/h)

2003average

FreeSpeed (km/h)

Urban Arterial - 50 km/h zone- Cars 91 86 62 58

Urban Arterial 60 km/h zone- Cars 80 75 69 71

Urban National 50 km/h sign

- Articulated Vehicles 89 92 61 63- Cars 89 98 65 69

- Rigid Vehicles 80 96 58 66

- Single decker buses 79 - 56 -

Urban Residential 50 km/h zone- Cars 20 36 43 45

* Exceeding speed limits applicable at the time of survey.


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2.2 Free speeds (rural)

The free speeds (rural) survey generally showed increased car free speeds onrural roads. Average observed car free speeds increased on motorways, dualcarriageways, national primaries and on regional roads.

The average free speeds of articulated and rigid vehicles appears to havechanged little over the period 2003 - 2005, having increased on dualcarriageways and regional roads but having fallen on national secondaryroads. Non-compliance rates for these vehicle types on rural roads remainhigh, varying between 45 94 per cent for articulated vehicles and between30-88 per cent for rigid vehicles.

Free speed (rural): Comparison of results for 2005 and 2003.

2005 ExceedingSpeed Limit (%)


2005 averageFree Speed

(km/h)


(km/h)

Motorway NP*- Articulated Vehicles 94 85 86 85

- Cars 15 23 109 106


- Single deck buses 100 - 95 -

Dual Carriageway NP*- Articulated Vehicles 87 60 85 82

- Cars 28 29 96 92



2-Lane NP*- Articulated Vehicles 83 73 85 85

- Cars 23 30 94 93



2-Lane NS*- Articulated Vehicles 48 34 76 77

- Cars 9 14 85 85

- Rigid Vehicles 30 46 74 79- Single deck buses 38 - 75 -

Regional Road (2-Lane)- Articulated Vehicles 45 17 76 71

- Cars 63 8 84 79



County Road (2-Lane)- Cars 37 10 75 77

* NP = National Primary Roads; NS = National Secondary Roads. Exceeding speed limitsapplicable at the time of survey.


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Chapter 3 Free speeds (urban) survey, 2005

3.1 Free speeds (urban) survey methodology

The free speeds (urban) surveys were carried out during June, July andAugust 2005. The locations chosen and methodology used were similar tothose used in the equivalent 1999, 2002 and 2003 surveys. The speedsmeasured reflect free speeds, i.e., the speed of the vehicle when it isunconstrained by either road geometry (e.g. overly narrow roads), weatherconditions (e.g. rain) or traffic (e.g. congestion).

On urban arterial roads, speeds were measured early in the morning between5.30 and 7.30 am, although in some locations in Dublin few readings ofvehicles were taken after 7.00am - as the traffic conditions could not bedescribed as free-flowing. The speed measurements on national and urban

residential roads were carried out in normal daylight hours (typically between9.30 a.m. and 5.30 p.m.). A number of different vehicle types were excluded,for instance: pedal cycles, commercial vehicles etc (see Appendix 1 for adiagram of included and excluded vehicle types).

The road classes surveyed were:

urban nationals at the 50 km/h speed limit;

urban arterials (main roads in urban areas) in 50 km/h speed zones;

urban arterials in 60 km/h zones, and

urban residentials in 50 km/h zones.

The free speed (urban) survey procedures are outlined in detail in Appendix 2.

Free speeds were only measured for cars on urban arterial and urbanresidential roads (due to a relative paucity of single / double decker buses,rigid or articulated vehicles on these roads especially during surveying hours).For urban national roads the speeds of cars, single decker buses, doubledecker buses, rigid and articulated vehicles were recorded separately withmeasurements taken at the 50 km/h sign on inbound traffic only.

Comments made in relation to trends in speeds are generally restricted to carspeeds, owing to limited sample sizes of both categories of buses, articulatedand rigid vehicles.

The same sites were chosen as in the 1999, 2002 and 2003 surveys1. Speed

was measured with radar meters. Efforts were made to ensure surveyorswere as inconspicuous as possible. The survey form was identical to that ofthe free speed (rural) survey (see Appendix 3).

1Appendix 7 shows the locations where urban free speed surveys were carried out.


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3.2 Free speeds (urban) survey results

The percentage of cars, articulated vehicles, rigid vehicles and single deckerbuses exceeding the speed limit is shown in Table 3.1. Owing to low sample

sizes, no figures are provided for double deck buses; caution should be takenin the interpretation of results provided below for single deck buses, as theyare based on very limited sample sizes.

The table shows that non-compliance rates are highest on urban arterial roadsin 50 km/h zones and on urban national roads at the 50 km/h sign.

The average observed car free speed within the 60 km/h speed limit on urbanarterial roads is 69 km/h, and is 62 km/h within 50 km/h zones. The averagecar speed entering the 50 km/h speed zone on urban national roads is 65km/h. By means of contrast, the average car free speed on urban residential

roads is only 43 km/h.

Table 3.1 Percentage exceeding speed limits on urban roads, 2005.

Avg. Speed(km/h)

NumberSpeeding

Number inSample

%Speeding

85th

PercentileFree Speed

(km/h)

Urban Arterial 50 km/h zone- Cars 62 698 770 91 69

Urban Arterial 60 km/h zone- Cars 69 610 766 80 79

Urban National 50 km/h sign- Articulated Vehicles 61 132 149 89 72

- Cars 65 981 1,105 89 79

- Rigid Vehicles 58 171 213 80 68

- Single decker buses 56 22 28 79 65

Urban Residential 50 km/hzone- Cars 43 133 664 20 52

Table 3.2 shows the distribution of observed free speeds for all urban roadtypes.

On urban residential roads, within 50 km/h speed limits, 80 per cent of carsare travelling under the speed limit. Of the 20 per cent that are not, four-fifthsare travelling at speeds between 50-60 km/h and the remaining one-fifth atspeeds in excess of 60 km/h.

On urban arterial roads, a total of 53 per cent of free-speeding cars in 50 km/hzones travel between 60-80 km/h, while 64 per cent travel at the same speed

when in 60 km/h zones.


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Table 3.2 Distribution of free speeds (%) on urban roads, 2005.


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Chapter 4 Free speeds (rural) survey, 2005

4.1 Free speeds (rural) survey methodology

The free speeds (rural) surveys were carried out in June, July and August2005. The locations chosen and methodology used were identical to thoseused in the equivalent 1999, 2002 and 2003 surveys. The speeds measuredreflect free speeds, i.e., the speed of the vehicle when the vehicle isunconstrained by either road geometry (i.e. sharp bends) weather conditions(e.g. ice) or traffic (i.e. congestion).

For the purposes of this survey, five types of vehicles were surveyed: cars,rigid vehicles, articulated vehicles, single-decker bus and double-decker bus.

The survey procedures mirror those used in previous surveys (see Appendix 3for sample survey sheets and Appendix 4 for survey details).

The surveys were carried out at the designated locations during working hours(9.30 am to 5.30 pm) Monday to Friday. Only speeds of vehicles that wereunconstrained - meaning speeds derived from vehicles with a headway / gapof at least 200 meters on roads where it was possible to exceed the speedlimit - were recorded.

All surveys were carried out in dry conditions. Surveyors were instructed tochoose vehicles in a random manner to avoid bias. Where a cluster of

vehicles arrived together the speed of the first one only was taken.

Surveyors were instructed to continue until the target number for each vehicleclass was reached or for a maximum of 2.5 hours, which ever occurs earlier.

4.2 Free speeds (rural) survey results

The percentage of cars that were exceeding the speed limit is shown in Table4.12. It must be stressed that speeds measured reflect free speeds, i.e.speeds of vehicles that were not constrained by traffic or road geometry, andshould not be interpreted as average speeds on roads concerned.

Partly influenced by lower speed limits set for articulated vehicles, rigidvehicles and buses, these vehicle types are generally more likely than cars tobe speed non-compliant despite the observed fact that the average speedsfor these vehicle types are substantially lower than those of cars. Average carfree speeds are highest on motorways, followed in turn by dual carriageways,national primary, national secondary, regional and county roads.

Observed speed transgression rates for cars (i.e. the percentage exceedingthe speed limit) are highest on regional roads, which as of January 20, 2005

2Detailed results of each site surveyed are available in Appendix 11.


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have speed limits set at 80 km/h; and lowest on national secondary roads forwhich 100 km/h speed limits apply.

Table 4.1 Percentage exceeding speed limits on rural roads, 2005.

Average Free

Speed (km/h)

Percentage

Speeding (%)

Number in

Sample

Speed Limit

(km/h)Motorway NP

- Car 109 15 938 120

- Articulated Vehicle 86 94 336 80

- Rigid Vehicle 89 88 207 80

- Single decker bus 95 100 23 80

Dual Carriageway NP

- Car 96 28 1,240 100




2-Lane NP

- Car 94 23 1,132 100




2-Lane NS

- Car 85 9 1,209 100

- Articulated Vehicle 76 48 84 80- Rigid Vehicle 74 30 172 80


Regional Road (2-Lane)

- Car 84 63 944 80




County Road (2-Lane)

- Car 75 37 752 80

Note: NP = National Primary Roads; NS = National Secondary Roads.


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Table 4.2 shows the distribution of free speeds by vehicle and rural road type.The modal (most frequent) car speed range is between 100-120 km/h onmotorways, 80-100 km/h on dual carriageways, national primary, nationalsecondary and regional roads and 60-80 km/h on county roads.

Table 4.2 Distribution of free speeds (%) on rural roads, 2005.


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Table 4.3 shows the free speed 50th

and 85th

percentiles [the 50th

percentilemeans the speed being exceeded by 50 per cent of traffic; and the 85

th

percentile, the speed being exceeded by only 15 per cent]. The 85th percentilecar free speed is highest on motorways followed in turn by dual carriageways,national primaries, regional roads, national secondaries, and county roads.

Table 4.3 Free speed percentiles on rural roads, 2005.

50th

Percentile Speed (km/h) 85th

Percentile Speed (km/h)

Motorway NP

- Car 108 119

- Articulated Vehicle 85 89

- Rigid Vehicle 85 100

- Single decker bus 95 98

Dual Carriageway NP

- Car 94 106




2-Lane NP

- Car 93 103




2-Lane NS

- Car 84 97




Regional Road (2-Lane)

- Car 85 98




County Road (2-Lane)

- Car 74 89

Note: NP = National Primary Roads; NS = National Secondary Roads.


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Table 4.4 compares the 2005 rural free speed survey to that undertaken in2003. The results show increased car free speeds on motorways, dualcarriageways, national primaries and regional roads. Average car free speedswere observed to have fallen marginally on county roads.

The average free speeds of articulated and rigid vehicles appears to havebeen relatively static over the period 2003 - 2005, having increased marginallyon dual carriageways and regional roads but having fallen marginally onnational secondary roads. Non-compliance rates for these vehicle types onrural roads remain high, varying between 45 94 per cent for articulatedvehicles and between 30-88 per cent for rigid vehicles.

Table 4.4 Free speed (rural): Comparison of results for 2005 and 2003.




(km/h)


(km/h)

Motorway NP*- Articulated Vehicles 94 85 86 85

- Cars 15 23 109 106



Dual Carriageway NP*- Articulated Vehicles 87 60 85 82

- Cars 28 29 96 92



2-Lane NP*- Articulated Vehicles 83 73 85 85

- Cars 23 30 94 93



2-Lane NS*- Articulated Vehicles 48 34 76 77

- Cars 9 14 85 85



Regional Road (2-Lane)- Articulated Vehicles 45 17 76 71

- Cars 63 8 84 79



County Road (2-Lane)- Cars 37 10 75 77

* NP = National Primary Roads; NS = National Secondary Roads.


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Appendix 1: Vehicle classes surveyed in freespeed surveys


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Appendix 2: Free speed (urban) surveyprocedures

The procedures used for the free speed (urban) survey mirror those used in

the 1999, 2002 and 2003 surveys. The survey measures free speeds - i.e. thespeeds of vehicles that were unconstrained either by road geometry (e.g.bends in roads) weather (e.g. ice) or traffic conditions (e.g. congestion).

The road classes surveyed were:

urban national (national primary and secondary roads throughtowns and villages) at the 50 km/h speed limit;

urban arterial (main roads in urban areas) in 50 km/h speed zones;

urban arterial in 60 km/h zones, and

urban residential in 50 km/h zones.

Free speeds were measured for cars, single deck buses, double deckerbusees, rigid and articulated goods vehicles on national roads but only carson urban arterial and urban residential roads (due to a relative paucity of othervehicle types on these roads especially during surveying hours).

The same sites were chosen as in previous surveys, where the sites werechosen according to the following criteria:

long, straight sections of roadway;

carriageway of at least 7 meters (except for urban residential);

sites where speed is relatively unaffected by geometry, traffic, traffic

lights, traffic calming measures, junctions, road works or parking,and

sites where it is feasible to drive faster than the speed limit.

Speed was measured with radar meters. Effort was made for surveyors to beas inconspicuous as possible. For national roads the speeds of cars, rigid andarticulated vehicles were recorded separately. Measurements were taken oninbound traffic only at the 50 km/h sign. On urban arterial roads, speeds weremeasured early in the morning between 5.30 to 7.30 although in Dublin after7.00 in the morning few readings of vehicles were taken as the trafficconditions could not be described as free-flowing. The speed measurements

on nationals and on urban residential roads were carried out in normal daylight hours (typically between 9.30 a.m. and 5.30 p.m.).

The surveys were carried out in dry conditions. Surveyors were instructed tochoose vehicles in a random manner to avoid bias, where a cluster of vehiclesarrived together the speed of the first one only was taken. The target samplesize for surveys on urban national roads was: 140 cars, 90 rigid vehicles and30 articulated vehicles [no quotas were allocated for either type of bussurveyed]. The target sample size for urban residential and urban arterialroads was 140 cars (no buses, rigid or articulated vehicles were surveyed forthese roads). Surveyors were instructed to continue until the target for eachvehicle class was reached or for a maximum of 2.5 hours, which ever occursearlier.


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Appendix 3: Sample free speed survey sheet


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Appendix 4: Free speed (rural) surveyprocedures

The road sections chosen for the survey were located based on co-ordinates

provided by ARUP Consulting Engineers / PMS Pavement ManagementServices Ltd (who conducted the 1999 Survey). The 1999 sites had beenselected to fulfil a number of different criteria:

presence of gateway / parking area so as to avoid been seen (ifpossible) and be safe;

design speed > 80 km/h;

the site must not be at a bend in the road, not be near a junction,bridge or road-side developments, and

the site must not be within a mile of road works.

Vehicle speeds were measured using radar speedmeters. Prior to use eachradar speedmeter was checked using a calibrated tuning fork. The instrumentwas placed so as to measure the speeds at a range of 100-200 meters.

Free speed surveys were carried out at the designated locations duringworking hours (9.30 am to 5.30 pm) Monday to Friday. Only speeds fromvehicles that were unconstrained - meaning speeds derived from vehicles witha headway / gap of at least 200 meters - were recorded.

All surveys were carried out in dry conditions. Surveyors were instructed to

choose vehicles in a random manner to avoid bias, where a cluster of vehiclesarrived together the speed of the first one only was taken.

Five vehicle classes were recorded: cars; single deck buses; double deckbuses; rigid vehicles; and articulated vehicles. The target sample size at eachlocation was: 140 cars, 90 rigid vehicles and 30 articulated vehicles.Surveyors were instructed to continue until the target for each vehicle classwas reached or for a maximum of 2.5 hours, which ever occurs earlier.


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Appendix 5: Free speeds (urban) surveylocations

Table A5.1 Urban national 50 km/h sign

IDCODE ROUTE COUNTY DESCRIPTIONNPU01 N17 Sligo At 50 km/h SL Curry Southside

NPU02 N18 Galway At 50 km/h SL north side of Gort town

NPU03 N8 Cork At Fitzpatricks Hotel, between the junctions ofN8/R635 & N8/R639

NPU04 N3 Meath Kells, on the east approach from Navan before thejunction of N3/R163

NPU05 N8 Laois Durrow, at the north approach to Durrow, before thejunction of N8/R434

NSU01 N78 Kildare Athy, at the north-eastern approach from Kilcullen

NSU04 N71 Cork West of Bandon, between the junctions of N71/R603& N71/R602

NSU05 N69 Limerick Tarbert on the N69, to the east of the junction of

N69/N67NSU07 N63 Galway At 50 km/h SL eastside of Moylough

Table A5.2 Urban arterial 60 km/h speed limit zone

IDCODE ROUTE COUNTY DESCRIPTION

ART1 N/A Dublin Rock road north of St. Helens Road

ART4 N/A Dublin Chapelizod road at the sports grounds

ART6 N/A Dublin James Larkin road slightly off Watermill road

ART10 N/A Dublin Clonkeen road south of Beach Park Road

ART11 N/A Dublin Naas road midway between Club road and Turnpikeroad

ART13 N/A Dublin Finglas road after Ballybogan road and north of Slaney

roadART14 N/A Dublin N11 Belfield just south of Belfield flyover

ART15 N/A Dublin Malahide road slightly north of Greencastle road


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Table A5.3 Urban arterial 50 km/h speed limit zone


ART2 N/A Dublin Morehampton road at Sachs Hotel

ART3 N/A Dublin Cabra road east of Annamoe road

ART5 N/A Dublin Templeogue road at Bushy Park

ART7 N/A Dublin N3 Navan road east of Kinvara avenue

ART8 N/A Dublin Dodder Park road north of Rathfarnham roadART9 N/A Dublin Lower Kilmacud road near junction with Kilmacud road

Table A5.4 Urban residential 50 km/h zone


RES01 N/A Dublin Brian Road Marino

RES02 N/A Dublin Broombridge Road

RES03 N/A Dublin Lorcan Avenue Santry, slightly to the west of Coolgariffroad

RES04 N/A Dublin Brookwood Rise, between Gracefield and RosemountAvenues

RES05 N/A Dublin Annamoe Road

RES06 N/A Dublin Glasilawn road, Griffith Avenue areaRES07 N/A Dublin Charlemont, at the missionary College

RES08 N/A Dublin Delwood road Blanchardstown, between Delwood walkand drive

RES11 N/A Dublin Abbey Park, just south of the Grange road


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Appendix 6: Free speeds (rural) survey locations

Table A6.1 Motorway


Myr01 M04 Kildare Just south of Maynooth exitMyr02 M07 Kildare 1 mile west of M9 interchange

Myr03 M01 Louth Just south of R170 Ardee junction

Myr04 M04 Kildare 1 mile south of Maynooth exit

Myr05 M07 Kildare 1 mile north of Naas/Allenwood junction

Myr06 M11 Dublin 1 mile south of roundabout at Shankill

Myr07 M07 Laois Portlaoise bypass

Myr08 M07 Laois Portlaoise bypass

Myr09 M01 Dublin Balbriggan bypass

Myr10 M01 Dublin Balbriggan bypass

Table A6.2 Dual carriageway

IDCODE ROUTE COUNTY DESCRIPTIONDCR01 N18 Clare 1 mile west of R463 Cratloe junction

DCR02 N03 Meath Close to Trim junction, R154

DCR03 N03 Meath Close to Trim junction, R154

DCR04 N03 Dublin 3 miles north of Clonsilla junction

DCR05 N11 Wicklow South of Newtownmountkennedy junction

DCR06 N18 Clare 2.5 miles east of R462 junction

DCR07 N18 Clare 1 mile west of R462 Cratloe junction

DCR08 N11 Wicklow South of Newtownmountkennedy junction

DCR09 N11 Wicklow Arklow by-pass

DCR10 N25 Cork Lower Glanmire road, Cork


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Table A6.3 National Primary (2-Lane)


NPR01 N25 Waterford 5 miles west of Dungarvan

NPR02 N08 Tipperary Between Horse & Jockey and Turnpike junctions

NPR03 N02 Monaghan 2 miles north of CarrickmacrossNPR04 N03 Cavan 2 miles south of Baeilieboro junction

NPR05 N04 Sligo 6 miles north of Boyle

NPR06 N22 Cork 1 mile east of R590/N22 junction

NPR07 N04 Leitrim Drumsna bypass

NPR08 N05 Longford 2 miles west of Longford

NPR09 N05 Mayo Swinford bypass

NPR10 N06 Offaly 1.5 miles west of Horseleap

Table A6.4 National Secondary (2-Lane)


NSR01 N60 Mayo 2 miles west of Claremorris

NSR02 N84 Mayo Just north of Partry

NSR03 N67 Galway Kinvara to KilcolganNSR04 N78 Kilkenny North of Castlecomer

NSR05 N58 Mayo Bellavary to Foxford

NSR06 N56 Donegal 2.5 miles south of Dunfanghy

NSR07 N60 Mayo 4 miles south of Castlebar

NSR08 N62 Tipperary 5 miles north of Templemore

NSR09 N59 Mayo 6 miles west of Newport

NSR10 N72 Kerry 3 miles east of N72/N22 junction near 4-arm junction


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Table A6.5 Regional road (2-Lane)


NNR01 R352 Galway From R353 to Powers Cross

NNR03 R178 Louth Between Carrickmacross and Dundalk

NNR05 R515 Tipperary Lattin, west of Tipperary town between Clashdrumsmith and ShronellNNR06 R438 Offaly 1 mile north of Taylor's Cross

NNR07 R499 Tipperary East of Dolla & Silvermines

NNR08 R403 Kildare Allenwood side of Prosperous

NNR09 R629 Cork South of Midleton.

NNR10 R742 Wexford Wexford to Curracloe

Table A6.6 County road (2-Lane)


NNL01 LP3210 Galway 2.4 miles from R358 at Mountbellew to Ballyforan

NNL02 LP111 Kildare Timahoe to R402

NNL03 LP333 Kildare South east of Naas R410 to north N7

NNL04 LP999 Wicklow Between R760 and Sraghmore

NNL06 L41 Offaly Tullamore - Ballinagar,2km east of Tullamore

NNL08 L34 Cork Ballynoe to R627 Ballyknock

NNL09 L35 Cork North Midleton

NNL10 L7 Wexford Enniscorthy Road to Ferns


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Appendix 7: Free speeds (urban) survey results by location, 2

Table A7.1 Urban arterial 50 km/h zone cars

Code Average Speed (kph)


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Table A7.3 Urban national 50 km/h sign - articulated vehicles



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Table A7.5 Urban national - 50 km/h sign - rigid vehicles



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Appendix 8: Free speeds (rural) survey results by location, 20

Table A8.1 Motorway - articulated vehicles



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Table A8.3 Motorway - rigid vehicles



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Table A8.5 Dual carriageway - cars



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Table A8.7 2-Lane national primary - articulated vehicles



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Table A8.9 2-Lane national primary - rigid vehicles



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Table A8.11 2-Lane national secondary cars



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Table A8.13 Regional road (2-Lane) articulated vehicles



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Table A8.15 Regional road (2-Lane) -rigid vehicles



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2005 survey of free speeds

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