# International Journey Time Benchmarking: Strategic Road Networks

## 

# Analysis Report

 

| Document Title    | International Journey Time Benchmarking: Strategic Road Networks -   |
|-------------------|----------------------------------------------------------------------|
| Summary Report    |                                                                      |
|                   |                                                                      |
|                   |                                                                      |
|                   |                                                                      |
| Version           | Date                                                                 |
| 1.0               | 23/10/2017                                                           |
| 2.0               | 9/11/2017                                                            |
| 2.1               | 14/11/2017                                                           |
| 2.2               | 23/11/2017                                                           |
|                   |                                                                      |
|                   |                                                                      |

## Acknowledgments

The Management Team responsible for the delivery of this work was as follows: 

 


- 
Adam Spencer-Bickle (Office of Rail and Road) 


- 
Jonah Aduan (Office of Rail and Road) 
 
  


- 
James Gleave - Project Manager (Transport Futures) 

 


- 
Derek Halden - Technical Lead (Loop Connections Ltd) 


The Team would like to thank all those who have assisted with data assembly, feedback and 


other observations to assist in delivering this project. 

 

## Introduction

Given the importance road users attach to the reliability and speed of their journey times1, the 


Office of Rail and Road (ORR) seeks clarity about how delays on the Strategic Road Network 


(SRN) compare with delays on similar networks in other countries. This report reviews an 

 


analysis of the delays experienced on England's SRN and how these delays compare with other 


countries. The work has been undertaken to assist ORR in delivering a robust evidence base on 

 
  


the performance of the network which is managed by Highways England. 

 
The work has been approached by: 

 

 
 
 
- 
Designing and developing the delay and congestion metrics to be used in the analysis taking account of the available data; 


- 
Sourcing comparable data for 13 countries, including England; 

 
 
 
- 
Analysing what this tells us about how delay and congestion in England benchmark with other countries. 
 
 
This report, and the accompanying infographic document, constitutes this analysis. This work 


has been undertaken by Transport Futures Ltd. and Loop Connections Ltd. 


## Objectives And Scope

The primary objective of the work was to benchmark delays and congestion on the SRN in 

 
England with equivalent networks in 12 other countries across Europe. This included identifying 

 


suitable metrics for the purposes of the benchmarking covering traffic delays and economic 


effects. 

  
These 12 nations were selected by ORR as part of a broader benchmarking exercise based on 

 


economic, demographic and road network characteristics. The countries included are: 

- Austria 
- Italy 
- Belgium 
- The Netherlands 
- Denmark 
- Republic of Ireland 
- France 
- Scotland 
- Finland 
- Spain 
- Germany 
- Wales 


The concept of a delay to a journey includes two main components: 

 
 
  

 

 
  


- 
The fastest achievable travel time if there is no delay; and 


- 
The measured actual travel time achieved. 
The total delay on a network is the difference between the travel time that could be achievable 

 
  


on the network and the actual time achieved, factored by the number of vehicles affected. The 


concept of congestion adds considerations of performance or expectation to the measures of 


delay introducing concepts such as traffic management, economic impact, experience, and 


other factors. 

 
  
This report compares road delays using these metrics across the 13 countries and adds 


observations about congestion based on these comparisons. 


## Methodology

The work has been approached in five main stages: 

 

- Defining comparable SRNs for each country 


- Traffic flow data assembly 


- Traffic Speed data assembly 


- Calculating delay and congestion 


- Understanding the economic effects 


This section describes the approach taken for each stage. 


 

## Defining Comparable Strategic Road Networks

For the purposes of this analysis, the SRN for England was defined as the network that is 

 
managed by Highways England. This network is shown in Figure 1. 


 
  
 
 
The approaches used by other countries to defining and managing SRNs were reviewed. SRNs 


link the major population centres within each country, and connect economic gateways such as 


ports and airports. Trunk road links including motorways dominate these networks in most 


countries, but other regional roads also make connections to more isolated towns which in 

 
England would be trunk roads, so these are also included. All of the countries covered manage 


many of these routes at a national or federal level, but many links are also managed by regional 

 


or local governments. 



The European Union has also defined a supra-national network of routes to connect economies 

 


across Europe: The Trans-European Road Network (TEN). All of the TEN links in the 13 

 
 
 
countries are part of their SRNs. 



In order to define comparable networks in each country to the Highways England network, 
 
broadly the same approach was undertaken as had been used to define the major road network 


(MRN) in England in a study for the Rees Jeffreys Road Fund but allowing for the fact that that 
 
   


network includes some roads that are not on the SRN, so judgement was applied in selecting 

 
 
links seeking to match where possible the logic for including links in the English SRN2. The 

 


English SRN possibly included some single carriageways that had been retained in the SRN for 


historical reasons, but which were not essential for connecting major towns due to the presence 


of new motorways so the difficulty was in matching such roads. However overall the same 


network logic could be followed in all countries. This comprised: 

- Selecting motorways and other similar major route categories designated for the 


purposes of strategic traffic in each country. 


- Adding other roads to ensure that all towns of greater than 50,000 people, and 


peripheral towns or population clusters of more than 25,000 people were connected by 


the network. 
 
- Adding other roads to ensure that ports with more than 2 million tonnes of freight, and 

 


the busiest airports by passenger traffic were connected to the network; 


- Checking that the network offers choices of routes to provide resilience using a 

 
geographical inspection of alternative routes between major centres. 


The MRN defined in England using these criteria was found to closely resemble the Highways 

 


England SRN. So using this approach enables a consistent approach across Europe using data 

 


on population centres, road networks and transport hubs available for all of the 13 countries. 


 
Population by neighbourhood was sourced from Socio-Economic Data and Applications Centre 


(SEDAC)3 and plotted in GIS. This was overlaid with the road network from Open Street Map 


(OSM) to check that all clusters of population of more than 50,000 people, or 25,000 in 


peripheral areas were connected to the network. Major ports and airports by freight and 


passenger volume were then added to the maps using location data by volume for these 


facilities sourced from Eurostat. Nomenclature of Territorial Units for Statistics (NUTS3) 


boundaries were then added including population density data for each NUTS3 area. 


 
Road links were then selected from OSM to define the SRN in each country as follows: 

1. Selecting motorways and principal roads from the digital road network defined in OSM. 


This included a manual check that all links in the TEN were included. 
 
  

 

 
2. Links to major ports and airports were then added. 


3. Population clusters were identified from the maps of settlement data. In most cases the 


towns being connected were discrete settlements of over 50k (or 25k in peripheral 


areas) residents. However, where the maps showed cluster of towns of less than 25k all 


within a few miles of each other these locations were also connected. 
  


4. Check the networks visually for coverage and resilience. 


This resulting network for the countries (excluding Finland for clarity) is shown in Figure 2. 


 
  

## Traffic Count Data Assembly

A review of available traffic count data for each country showed that it would not be possible to 


estimate traffic flows on each link of the SRN in each country from publicly available data. To 


estimate traffic flows at the locations where traffic delays were occurring, at a level of accuracy 


suitable for international benchmarking, estimated road capacities were used. There is an 


extensive literature on speed flow relationships on road networks which shows that averaged 


across entire networks two important thresholds can be identified: the points at which delays 


start to be observed by road type, and the maximum lane capacity by road type. The average 


flow where delays are observed is between these two thresholds. 

 
Road categories and capacities from DfT Transport Appraisal Guidance4 were validated using a 

 
sample of traffic count data from the UK, Ireland, Finland and Germany. For these four countries 


automatic traffic counter (ATC) data was available for hourly segments throughout the day 


allowing the build-up of flow and delay throughout the day to be analysed. 



The English data was available from MIDAS count sites across Highways England's network so 


sites in congested locations were selected to identify how flows and delays built up towards 


capacity. Figure 3 illustrates the curves for Motorways in the four countries. Delays build up on 
 
  


single carriageway roads from much lower flow levels when overtaking opportunities start to 
 
 
become limited and all vehicles are delayed to the speed of the slowest vehicle. Single 


carriageway traffic flows per lane rise to similar levels as for dual carriageways and motorways 


but only at vehicle speeds well below that sought by drivers. 


   
Based on analysis and inspection of the many curves for the various road categories it was 

 
 
decided to use average hourly flows in the analysis as shown in Table 1. In selecting these 


values two important points are of note. There was no evidence from the limited data that lane 


capacities per hour were significantly different in any country. This reflects the international 

 


literature for speed flow relationships used in traffic models which transfer well from country to 

 


country. 

  
 
Secondly, delays were evident on dual carriageways and motorways from 1500 vehicles per 


hour per lane upwards and there was no evidence of more than about 2500 vehicles per hour 


per lane being achieved. The curves demonstrate an average flattening of their tops at flows 


from 1900 vehicles per lane per hour. To represent a suitable value for average lane capacity at 

 


the point of delay somewhere between 1500 and 2500 vehicles per lane per hour an average of 
 
 
2000 vehicles per lane per hour was chosen as a conservative average estimate. Some three 


and four lane motorways achieved the high end of this and some the low end so overall there 


was no reason to separate out 2 lane motorways from wider roads. For single carriageways 

 


1000 vehicles per hour per lane was chosen, since at this level of flow delays to vehicles are 


building strongly even on roads with good overtaking opportunities. 


|                                      |      |                                           |     |     |     |
|--------------------------------------|------|-------------------------------------------|-----|-----|-----|
|                                      |      |                                           |     |     |     |
| Average Hourly Flows Under Congested |      |                                           |     |     |     |
| Conditions (per lane)                |      |                                           |     |     |     |
| 2000                                 |      | Urban roads with speed limits of 50kph or |     |     |     |
| less                                 |      |                                           |     |     |     |
|                                      |      |                                           |     |     |     |
|                                      |      |                                           |     |     |     |
| Rural single carriageway roads       | 1000 |                                           |     |     |     |
| Dual carriageways and motorways      | 2000 |                                           |     |     |     |

In practice it is often junction capacity and road context rather than lane capacity that constrains 
 
 
maximum flows, and the delays experienced on the network. 


 
For the purposes of benchmarking, the average values in Table 1 represent an acceptable level 


of accuracy for comparing average levels of delay. To achieve a higher level of accuracy the 

 


actual traffic flows would need to be estimated across all countries using real traffic flows at 


frequent intervals along every road which would demand a coverage of traffic counts well 
 
beyond that available. Using a common value of 2000 should deliver fairly robust benchmarking 


results for dual carriageways and motorways. Greater caution is needed when comparing single 


carriageways as their flow and delay characteristics are more variable. 


## Journey Time Data Assembly

There are many potential sources of link speed data, but the source most widely used by the 


public is journey times from Google Maps. Google's Android system operates about half of the 
  


mobile phones in the UK and 90% of smartphones globally. These phones are precisely located 
 
  


and tracked on the road network when travellers have activated location services (roughly 85­


90% of travellers). The Google data therefore represents by far the world's largest source of 


data showing the journey times on the road network. Given the multiple occupancies of many 


road vehicles more than half of all vehicles on the strategic road network are being tracked by 


Google. 

  
Google themselves process this data and share it openly for public use, principally for journey 

 


planning and route navigation. The data is made available in real time showing not just speeds 


but disruption and other delays on the network and supports navigation using Google's mapping 


systems and many third party applications which use the Google API under Google terms and 


conditions. Journey times can be accessed on Google's servers for any date and time, so the 


data can be sampled under Google's terms and conditions for the purposes of calculating road 


delays. If the public use and trust these journey times it is appropriate that ORR, acting on 
 
 
behalf of the public, should benchmark congestion using data which the public already trusts. A 

 
license was purchased to access the Google data via their web-servers. 



Data on journey times was repeatedly accessed through the Google Application Program 


Interface (API) until the journey times at 15 minute intervals had been obtained across the 
 
SRNs for the 13 countries. The sampling method used all journey times for 10th October 2017. 



Weekly expansion factors were derived from data for the full week commencing 8th October 


2017. The data was then expanded from weekly to annual values using comparable data for the 


second Tuesday of each month. These expansion factors allowed the 10th October journey 


times to be factored to annual averages. 



To extract the data from Google, origin and destination points were identified at junctions on the 


SRN for each country using co-ordinates for these junctions defined using OSM networks. The 


SRN was then built up as a series of nodes and waypoints by road number. This process was 

 


not without challenges. Initial attempts to match co-ordinates resulted in a number of errors 


where diversions off the intended route were observed. However, these issues were overcome 


with manual checking of the routes built by Google in each country. Routing errors were 


resolved by amending waypoints as required to specify the network accurately using the 


standard Google waypoint input format. The route was then specified as a set of RouteIDs 


made up of LegIds and BaseIDs consistent with the Google format for connecting nodes and 


waypoints. 

 

## Calculating The Delay And Congestion Metrics

To calculate delay, the free flow speeds were estimated as the best average travel time 


achieved in any 15 minute period on any Leg. To avoid confusing road delays with small 


variations in journey times (for example travel time of 10 minutes across a link at 2am, 


compared to 9 minutes at 3am), only delays to the free slow time of more than 15% of the 
 
  


minimum value were included. The minutes of delay on each LegID were then aggregated 


across the network based on estimated traffic flows on each Leg to calculate the total travel time 


delay for the defined network. 



The total delay metric used by DfT on the English SRN is: 

 


- 
(The larger of (Journey Time - Free-flow journey time) or zero] * Expected Flow)/Total 
Vehicle km on the SRN (1) 5 

 
As discussed above, only limited data is available about traffic flows on the SRNs across 

 


Europe. The errors that would have been associated with estimating traffic flows across Europe 


5 Note that the Journey Time on any link of the network is the lower of the measured travel time or the speed limit. Speed limit data for each LegID was extracted from Google. This data is based on automatic recognition of speed limit signs in Google Steetview and Google note that there can be errors in this data. To ensure that accurate speed limits were used, on legs where the average of the observed speeds between 1am and 4am exceeded the speed limit from Google for the LegID, the Googlle LegID speed limit was replaced with the national speed limit for that type of road in each country. 


 

 

 

 
 
    
would potentially be greater than any differences in congestion. To ensure a consistent 

 

 
 
approximation to the vehicle flows across the European Countries at the points in the network 


where delay was observed an average lane capacity at congested locations was used to 


estimate the volume of traffic delayed.6 
  
Where delays are observed, the actual flow on the road may be slightly above or below the 


estimated flow based on road capacity, but averaged across a large area, these lane capacity 


estimates offer a consistent way to ensure that delay could be benchmarked in a consistent way 


in all countries with acceptable accuracy. 



Since the total traffic flow on the SRN is not known for countries other than England, equation 

 


(1) was modified to show the delay per mile of road to ensure a comparable metric for each 


country: 
 


 
 
- 
(The larger of (Journey Time - Free-flow journey time) or zero] * Estimated Road 
Capacity)/Miles of SRN (2) 


To ensure that the benchmarking delay metric accurately reflected the Highways England metric 


the congestion in England was also calculated using equation (1). The analysis was undertaken 


separately in each direction for each part of the SRN. Table 2 compares the Highways England 

 


calculation approach with the benchmarking calculation approach used in this work. 


 
 
  

## Table 2 - Comparing The Highways England Kpi Approach And The Orr Approach Highways England Orr Approach

|                                                 |
|-------------------------------------------------|
| LegID with an estimate of traffic from the best |
| available data for that link or if none is      |
| available a default flow for the link type      |
| assuming that the link is running near          |
| capacity estimated from the capacity of that    |
| type of road as showing in Table 1.             |


 

 


Expected flow is taken from MIDAS counting sites associating each site with a road link and where necessary combined data to obtain an average or sum of multiple sites to estimate the flow on each link. Expected Flow is calculated as a combination of flows measured in the given 15-minute and similar time periods. Time periods without observed data are infilled with data from time periods either side of the period required. Flows without data after this process are infilled with the monthly average values for the link by day and night 
 
  

 

 

 


Road speeds are extracted from the Trafficmaster data on sampled days in each 

 
 
Travel times were extracted from the Google database based on their "best-guess" of the 


6 Where there is no delay at a location, the traffic flow is not used since zero delay delivers a zero result from equation (1). 

                                               

 

 

 

 

## Highways England Orr Approach

month are calculated for each 15 minute journey time on any link at any time of day. 

period as the sum over all 15 minute periods The representative daily delays for 10th of (Delay) / sum over all 15 minute periods of October 2017 were calculated for each 15 
( [Expected Flow] * [Length of link] ). Using minute period as the sum over all 15 minute the Trafficmaster data journey times are periods of (Delay) / sum over all 15 minute calculated from data for cars only. These are periods of ( [Expected Flow] * [Length of link] 
car speeds from long term historical data 
) To eliminate the effect of random variation capped at the recorded speed limit. The during periods of no delay, delays of less 


speed limit is used as the basis for free flow than 15% to the travel time were ignored. 

journey times. 

Travel times were capped at the value which would be achieved when travelling at the 

## Delay Is Presented Per Vehicle/Mile And Speed Limit.



calculated as the total delay divided by the total vehicle miles from UK traffic count data. 

Delay is presented per vehicle/mile by taking the total delay and dividing this by the estimated total vehicle miles on the strategic road network from DfT statistics for the Highways England network (91.9 billion vehicle miles in total). 

As noted above, traffic flow data is not available for all of the SRN in each country so for the 


purposes of international benchmarking different delay metrics were needed. The three 


measures of delay used for the benchmarking are described in Table 3. 


 

## Table 3 - Benchmarking Delay

| Delay Measure                                                             | Calculation Method                                                      |     |     |                                                                     |     |
|---------------------------------------------------------------------------|-------------------------------------------------------------------------|-----|-----|---------------------------------------------------------------------|-----|
| Delay by vehicle                                                          | Travel times were extracted from Google based on their "best-guess" of  |     |     |                                                                     |     |
| miles by road                                                             | the journey time. Tuesday 10                                            |     |     |                                                                     |     |
| th                                                                        |                                                                         |     |     |                                                                     |     |
| October was sampled at 15 minute                                          |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| length                                                                    | interval periods and these results were annualised using weekly and     |     |     |                                                                     |     |
| monthly expansion factors. The time delays greater than 15% of the        |                                                                         |     |     |                                                                     |     |
| free flow time were factored by the number of lanes of congested traffic  |                                                                         |     |     |                                                                     |     |
| and the average flow per lane in congested traffic to estimate the total  |                                                                         |     |     |                                                                     |     |
| vehicle delay on the SRN. The delay metric was then presented as the      |                                                                         |     |     |                                                                     |     |
| number of hours of delay per mile per day.                                |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| The average                                                               | Where traffic is delayed by more than 15% of the free flow journey time |     |     |                                                                     |     |
| number of hours                                                           | on a link, the length of the road link was factored by the number of 15 |     |     |                                                                     |     |
| when traffic is                                                           | minute time periods affected, and summed across the country. The total  |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| delayed                                                                   | was then divided by the total length of the network to calculate the    |     |     |                                                                     |     |
| average number of hours of delay on the SRN.                              |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     | The travel time from each NUTS3 population centroid to the point on |     |
| the SRN closest to strategic cities, ports and airports was calculated at |                                                                         |     |     |                                                                     |     |
| 15 minute intervals as for the delay by vehicle miles and resident        |                                                                         |     |     |                                                                     |     |
| population measure.                                                       |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| Effects of delay on                                                       |                                                                         |     |     |                                                                     |     |
| connections                                                               |                                                                         |     |     |                                                                     |     |
| between the                                                               |                                                                         |     |     |                                                                     |     |
| population and the                                                        |                                                                         |     |     |                                                                     |     |
| largest cities, and                                                       |                                                                         |     |     |                                                                     |     |
| the largest airports                                                      |                                                                         |     |     |                                                                     |     |
| in each country                                                           |                                                                         |     |     |                                                                     |     |
| The population catchment for the free flow times was compared with the    |                                                                         |     |     |                                                                     |     |
| population catchment during peak hours of the day as follows:             |                                                                         |     |     |                                                                     |     |
| -                                                                         |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| Population of NUTS3 area within 30, 60 and 120 minutes of                 |                                                                         |     |     |                                                                     |     |
| each strategic destination                                                |                                                                         |     |     |                                                                     |     |
| -                                                                         |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| Peak hour travel times were the average of journey times at               |                                                                         |     |     |                                                                     |     |
| 8am, 9am, 5pm and 6pm.                                                    |                                                                         |     |     |                                                                     |     |
| -                                                                         |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
| Free flow journey times were the minimum journey times                    |                                                                         |     |     |                                                                     |     |
| achieved.                                                                 |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |
|                                                                           |                                                                         |     |     |                                                                     |     |

## 

These measures of delay have been used to compare the SRN in England with traffic delays in 

 

 
the 12 other countries. The value of these delays to each country will depend on many factors 


such as effects on productivity based on the character of the local economy. It is beyond the 


scope of this work to benchmark the economies of the countries, but the above measures of 


delay could be combined with other economic indicators as part of a broad benchmarking study 


if required. 

 
     
 

## The Strategic Road Networks

Figure 4 shows that England's SRN has a higher proportion of rural single carriageways than 
  

 


other densely populated countries. Whereas long distance routes to towns on the periphery of 


countries like Italy, France and Spain are connected by dual carriageways, England still relies 


on single carriageways for parts of long distance routes. Only Finland, Scotland, Wales and 


Ireland rely more heavily than England on single carriageways to connect their main population 
 
settlements. 

  
Road congestion is often seen as mainly an urban problem. The SRNs are defined as the routes 
 
  


between urban areas with built up areas, such as trunk roads passing through towns, 
 
 
accounting for less than 2% of the length of the SRNs in all countries. 


 
Only Belgium and the Netherlands have more of their SRN passing through areas with 


population densities exceeding 500 people per square km as defined by the European NUTS3 


geography population density classification. 


 
Figure 5 shows that England, the Netherlands, Italy and Belgium are the four countries with 
  


more than 30% of the SRN passing through areas with medium population densities of between 


251 and 500 people per square km. 


## Comparing The Highways England Delay Measure With The Orr Benchmarking Approach

Delays on the English SRN were calculated using the methodology described in Table 2. This 

 


method differs from the DfT approach in two important respects: 

 

 


- 
The travel times are extracted from Google rather than from Trafficmaster as in the DfT 
 
approach. 

 
 
- 
The vehicle flows where the delay occurs use average lane flows from Table 1 rather 
 
 
than the actual measured flows on each part of the network as in the DfT approach. 
Table 4 summarises the key statistics from the calculation of the Highways England KPI using 
  


the ORR methodology 
 

|           |     | Item   |
|-----------|-----|--------|
|           |     |        |
| Value     |     |        |
|           |     |        |
|           |     |        |
|           |     |        |
| of        |     |        |
|           |     |        |
| vehicle   |     |        |
|           |     |        |
| delay     |     |        |
|           |     |        |
| on        |     |        |
|           |     |        |
| the       |     |        |
|           |     |        |
| SRN       |     |        |
|           |     |        |
| 841       |     |        |
|           |     |        |
| billion   |     |        |
|           |     |        |
|           |     |        |
|           |     |        |
| vehicle   |     |        |
|           |     |        |
| miles     |     |        |
|           |     |        |
| on        |     |        |
|           |     |        |
| Highways  |     |        |
|           |     |        |
| England   |     |        |
|           |     |        |
| network   |     |        |
| 7         |     |        |
|           |     |        |
| 91.9      |     |        |
|           |     |        |
| billion   |     |        |
|           |     |        |
|           |     |        |
|           |     |        |
| delay     |     |        |
|           |     |        |
| per       |     |        |
|           |     |        |
| vehicle   |     |        |
|           |     |        |
| mile      |     |        |
|           |     |        |
| (seconds) |     |        |
|           |     |        |
| 9.15      |     |        |
|           |     |        |

An average level of delay of around 9 seconds per vehicle mile has been consistently reported 


annually for the English network8. The averaging approach used in this project for 

 


benchmarking delays using internationally available data delivers a value of 9.15 is consistent 


with this. 

 
  

                                              

 

## Benchmarking Delays On The Srn

There are 74 hours of vehicle delay per mile of English SRN per day. Only Germany has more 


hours of delay per vehicle mile on its SRN per day. Figure 6 shows that most countries have 


levels of delay less than half of the English level but Denmark, the Netherlands and Belgium 


also have higher than average levels. 

 
  
 
  

 


Figure 7 shows that the higher levels of delay in Germany are at least partly due to traffic 

 
congestion lasting for longer across more of the network in Germany than elsewhere. 


 

 


Nearly a quarter of available hours by length of SRN are delayed in Germany. This compares to 


9-12% of hours by road length in England, Scotland, the Netherlands, Denmark and Wales. This 

 
 
 
also means that the delay of 74 hours per mile on the English SRN is twice as concentrated by 


network hours and length as the 88 hours per mile on the German SRN. 

Further analysis gives some insight into why some countries have less delay than others. 


 
Some countries use tolled roads to relieve the pressure on untolled roads and to offer vehicle 


users a choice of a premium network. Others like England largely use tolls more sparingly 


predominantly as part of funding for expensive assets such as estuarial crossings. Figure 8 

 
compares the delay for untolled roads with the average for all roads. France, Italy and Ireland 
 
 
have higher levels of delay on the untolled routes with the effect being particularly marked for 


France, where there are 50 hours of delay per mile on the untolled network, more than twice the 


average of 22 for all roads. Tolled roads in these nations form a comparatively higher proportion 

 

 


of the strategic road network compared to other nations. 


## Roads9



There are much greater delays per mile on single than dual carriageways and motorways, 


particularly in more densely populated countries. Although England may be more dependent on 


single carriageways for strategic network connections to towns and ports it has less delay per 


mile on these roads than the Netherlands, Denmark and Germany. Perhaps more significantly English dual carriageways and motorways have only 28 hours of delay per mile which is less 

                                              

 
 
  


than 30 in the Netherlands, 34 in Denmark and 77 in Germany. Despite some roads in Germany 

 
 
having no speed limit, there are few instances of higher average speeds on road links in 

 
Germany than elsewhere so this is not a factor in this higher level of delay. 



The motorways around major cities have amongst the highest levels of delay. Many cities have 


circular or semi-circular motorways round them and Figure 10 compares the hours of delay per 


mile for these routes. Both the inner and outer orbital motorways for Madrid have been included 


in this analysis which perhaps contributes to the lower level of delay seen there. The outer orbital is more remote from the city. In contrast for Brussels, the semi-circular motorway is well 
  


within the urban fringe. 


 
Rome's orbital motorway forms a close boundary around the city and has 276 hours of delay per 

 


mile with delays affecting 22% of the routes hours by length. In contrast the M25 around London 


experiences delays for 20% of hours by network length accounting for 227 hours of vehicle 


delay per mile. 


## 


## Benchmarking Travel Times To Key Nodes

Reliable travel times to reach key destinations can be particularly important for economic 


competitiveness. Figure 11 shows one-hour population catchments in the peak and off-peak 

 


periods to Major Cities in England. 



Making a similar comparison for the major cities in the 13 countries the effects of peak hour 
  

 


traffic on London can be seen to be particularly marked. London has the largest free flow 


catchment but this falls behind Paris, Brussels and Madrid in the peak period. 


## Figure 12 - Peak And Off-Peak Catchments From City Nodes On The Srns

 
A similar picture is seen for the airports as key international gateways from each country. 


## Figure 13 - Peak And Off-Peak Catchments From Major Airports


 


Comparing a selection of less central towns including ports like Dover and Rotterdam shows 


that delays on the road network are not distributed evenly in the 13 countries. 

 

## Figure 14 - Peak And Off-Peak Catchments For Key Towns And Cities Conclusions

This analysis has shown that delay on SRNs in 13 countries varies from 1% of hours by length 

 


of network in Finland to 24% of hours by length of network in Germany. 

 
  

 
 
Although England's SRN experiences an average number of hours of delay by network length, 


this results in more hours of vehicle delay than all countries other than Germany. In Germany 
 
there are 88 hours of delay per mile of SRN compared to 74 hours of delay per mile in England, 

 
 
but the delays in England are far more concentrated geographically and temporarily than in 


Germany. The higher delays in England are partly related to the reliance on single 
  


carriageways, which typically experience higher delays, in England for some strategic roads. 

  


Towns of 20,000 people or more in most countries are largely served by dual carriageways. 


 

 
There may also be some influence from the way the networks were defined, since the English 


SRN includes additional single carriageways which it is possible would not have been selected 

  


using the methodology described. Lower levels of delay are associated with less dependence 


on single carriageways for strategic links and the level of tolling on the network. In countries 


such as France and Italy with large tolled networks complementing the free networks the delays 


on the untolled SRN is more than three times the delay on the tolled network. For example, in 
  
 
 
France the 50 hours per day per mile for untolled toads compares with 13 hours per day per 


mile for tolled roads, and the equivalent figures for Italy are 35 for untolled roads and 15 for 


tolled roads. 

 
The concentration of delays on the English network results in a greater peak to off-peak 

 


variance in journey times compared with other countries. It may be that there is less flexibility in 
  

 


England about the timing of economic activity leading to the more concentrated peaks. 



The data collection for this work from public sources has shown how widely available consumer 


data can be used to benchmark the experience of users of the road network. There are many 


ways that the data assembled for this work could be further analysed to consider effects relating 


to economic links and connections. This analysis has considered these effects only from the 


perspective of the travel times to key nodes, but suggests that reductions in peak hour delays 


on the road network could enhance English competitiveness, particularly the labour market 


catchment for London.