Knowledge Compendium

For pre-2009 projects, please see our index of archived project pages.

Highways Agency Carbon Routemap: opportunities for a national low carbon transportation system

Publication Details

Authors: Arup
Document Reference: 536706
Publication Date: July 2014
Assessment Level: Additional to the evidence pool
Peer Review Information: No

Exec­u­tive Summary

Scope of the High­ways Agency car­bon Routemap

The High­ways Agency Routemap cov­ers the direct and indi­rect green­house gas emis­sions asso­ci­ated with the Agency’s organ­i­sa­tional activ­ity, the high­way asset base and asso­ci­ated sup­ply chain, and those aris­ing from the use of the net­work by cus­tomers. To aid with com­mu­ni­cat­ing this scope, three emis­sions cat­e­gories are used through­out the report:

Cor­po­rate (Organ­i­sa­tional) car­bon emis­sions: the direct and indi­rect emis­sions asso­ci­ated with the oper­a­tion of the strate­gic road net­work (SRN) by the High­ways Agency.

Asset base car­bon emis­sions: the emis­sions aris­ing as a result of con­struc­tion and main­te­nance activ­ity of the strate­gic road net­work and the sup­ply chain that exists to deliver this (i.e. those emis­sions effec­tively embod­ied within build­ing the SRN).

Road user car­bon emis­sions: the emis­sions aris­ing from the use of the SRN by par­ties other than the High­ways Agency and its part­ners, i.e. the com­mer­cial traf­fic and trav­el­ling pub­lic — the Agency’s cus­tomer base.

The High­ways Agency car­bon Routemap cov­ers the period 2013 to 2050 and takes as its base­line posi­tion in 2013 car­bon emis­sions based on his­tor­i­cally mea­sured or cal­cu­lated data gath­ered over the period 2009 to 2013.

In pro­ject­ing for­ward, three future sce­nar­ios to 2050 are cre­ated from a com­bi­na­tion of his­toric trends, pub­lished fore­casts and bench­marks, mod­elled depen­den­cies and expert knowl­edge of key dri­vers of car­bon emis­sions. These sce­nar­ios are:

Base­line: a ref­er­ence sce­nario with low tech­nol­ogy take up and when the High­ways Agency is not proac­tive in its efforts to meet the low car­bon agenda.

High­ways Agency’s cur­rent tra­jec­tory: intended to rep­re­sent as closely as pos­si­ble the Agency’s cur­rent tra­jec­tory where by tech­nol­ogy take up is low, although the Agency is proac­tive within the low car­bon agenda.

An intel­li­gent: low car­bon trans­port sys­tem: this sce­nario com­bines high tech­nol­ogy take up with a trans­for­ma­tion of the SRN into an intel­li­gent, low car­bon trans­port sys­tem, and where the High­ways Agency is proac­tive in meet­ing the low car­bon agenda.

Key find­ings

The 2013 GHG emis­sions aris­ing from con­struc­tion and main­te­nance of the SRN and its asso­ci­ated sup­ply chain are over dou­ble that of the High­ways Agency as an organ­i­sa­tion itself. Taken together both are small when con­sid­er­ing SRN use which accounts for emis­sions some 90 times greater than the com­bined asset and organ­i­sa­tional emissions.

Fur­ther analy­sis of the Routemap suggests:

Cor­po­rate /organisational car­bon emis­sions: are made up of a range of com­po­nent parts (estate build­ings, water use, office pro­cure­ment, busi­ness travel, etc.) but are largely weighted by net­work energy demand, par­tic­u­larly light­ing. They there­fore see a marked reduc­tion in all sce­nar­ios due to assumed energy grid decar­bon­i­sa­tion. Set against this con­text is the like­li­hood that elec­tric­ity bills will increase in order to fund the elec­tric­ity grid’s decar­bon­i­sa­tion. This makes it a pri­or­ity that the High­ways Agency should con­tinue its efforts towards reduc­ing elec­tri­cal demand in order to min­imise its expo­sure to energy price increases. Addi­tion­ally, demand reduc­tion is a key con­tri­bu­tion to national grid decar­bon­i­sa­tion in itself, mak­ing it less expen­sive to install the nec­es­sary infrastructure.

Asset base car­bon emis­sions: in 2013 are some three times higher than cor­po­rate emis­sions and show a marked increase in the short term in line with the High­way Agency’s planned bud­get. This means emis­sions from con­struc­tion are pro­jected to almost dou­ble over the next five years from 0.5 MtCO2e in 2014 to over 1.2 MtCO2e by 2020. There­after expen­di­ture is assumed to level off and run steady to 2050. Over­all the trend is of slow decline and the con­struc­tion sup­ply chain remains a sig­nif­i­cant car­bon emit­ter for the Agency out to 2050. This antic­i­pated short term sharp increase is of par­tic­u­lar con­cern when set against the pri­or­ity of keep­ing atmos­pheric car­bon diox­ide con­cen­tra­tions within a global bud­get of less than 450ppm. This pend­ing cli­mate change risk is an issue that the Agency should move to man­age and address directly through tak­ing mit­i­gat­ing efforts in the short term.

Road user car­bon emis­sions: are orders of mag­ni­tude greater than those aris­ing from asset base /supply chain car­bon emis­sions. In sce­nario 1 trends in travel demand over­whelm the Agency’s efforts to man­age speed and con­ges­tion, and vehi­cle drive trains see only mod­est improve­ments in car­bon effi­ciency through to 2030. Under the assump­tions of this sce­nario, there is almost no net reduc­tion in road user emis­sions by 2050.

Sce­nario 2 takes into account improve­ments that the High­ways Agency can imple­ment through a degree of roll out of smart motor­way tech­nol­ogy and improve­ments to con­gested links lead­ing to a sig­nif­i­cant 2.9 MtCO2e emis­sions saving.

Sce­nario 3 sees sub­stan­tial change in dri­ve­train mix of vehi­cle stock on the road together with effi­ciency improve­ments to cur­rent tech­nol­ogy norms. Smart motor­ways would be rolled out to most of the net­work and ‘mile a minute’ aver­age speeds are realised for all links on the motor­way and trunk A-road net­work. This aspect in par­tic­u­lar will require a proac­tive approach by the High­ways Agency enabling the tran­si­tion to smart motor­ways with focus on con­struc­tion ini­tia­tives alle­vi­at­ing con­ges­tion and adapt­ing the base infra­struc­ture sys­tem, together with shifts in oper­a­tional approaches to traf­fic man­age­ment. Over­all, this results in an 83% reduc­tion (some 25.5 MtCO2e) by 2050. The con­clu­sion is that with tar­geted action on the roll–out of smart motor­ways and works to ease bot­tle­necks, the Agency can deliver.

Next steps

The pub­li­ca­tion of this low car­bon Routemap posi­tions the High­ways Agency as a leader in under­stand­ing the cli­mate change impacts of the national high­way sys­tem. Although the Agency may have less influ­ence within this sphere than it might like, the work has bro­ken new ground in mea­sur­ing the scale of emis­sions, iden­ti­fy­ing where they reside, and deter­min­ing what will need to hap­pen if we are to meet national reduc­tion commitments.

As a major infra­struc­ture provider the High­ways Agency is enter­ing an excit­ing new phase that will rad­i­cally change the way strate­gic roads are funded and man­aged. The oppor­tu­nity of this tran­si­tion is to use the low car­bon Routemap to bring about change to the way cli­mate change is dealt with when deliv­er­ing crit­i­cal national infrastructure.