Impact of Expressways on Emissions

Sudhir Gota

Expressways are often packaged as a silver bullet solution to reduce congestion and emissions. While, expressways provides fast and reliable movement, but it is effective only when one optimally prices the travel. Building roads without pricing it optimally yields high induced development and traffic thereby causing gridlock again – a case similar to new mall providing discounts to generate the footfalls.

Huge number of literature has been generated from around the world showing that an expressway which provides cheap mobility often induces more traffic and thus builds congestion in the network. But, not much research has been carried out on life cycle assessment of such expressways. Three corridors in India and one in VietNam were considered for investigation.  The projects were essentially two lanes to four lane conversion projects. The VietnNam corridor was a new expressway project.

The impact has been considered in two stages – short and long term.

a.       Short Term: It is incorrect to assume that higher speeds always reduce emissions

It's a myth that higher the speed, lower would be the emission.  On the contrary, the emission is lowest when speed is in the range of 40-60 kmph. Lower emissions not only mean better environment but also saving precious fuel. The impact of capacity expansion on corridors during the first 5 years after the improvement after neglecting the induced traffic is shown below.  

Project	Scenario	Description (Kilo tons CO2/Km)					~V/C	Avg Speed (kmph)
		1st Year	2nd Year	3rd Year	4th Year	5th Year
Belgaum-Dharwad	BAU	2.65	2.78	2.92	3.07	3.22	0.45	58
	After Project	2.69	2.83	2.97	3.12	3.27	0.2	80
Salem-Namakkal	BAU	2.28	2.39	2.51	2.63	2.77	0.4	59
	After Project	2.32	2.43	2.55	2.67	2.81	0.2	80
Surat-Manor	BAU	5.959	6.452	7.434	7.962	8.107	0.85	41
	After Project	5.415	5.842	6.327	6.659	7.213	0.4	76
Ho Chi Minh -Long Thanh-Dau Giay	BAU	3.099	3.354	3.63	3.94	4.265	0.52	57
	After Project	3.211	3.476	3.763	4.073	4.41	0.23	80

Impact of Road Capacity Expansion in Corridors during Five Years 

(excluding induced traffic impact)

It is clear that even during initial years the capacity expansion may not yield CO2 savings.  The savings are obtained only in the projects which has existing speed below 40kmph. Increasing the capacity of road which already facilitates speed between 40-60 kmph is iatrogenic. The spur in speed can have disastrous effects on emissions if it exceeds the 40-70 kmph range.

b.      Long Term: Induced traffic should not be neglected in emissions quantification

An increase in traffic speed reduces the cost thereby attracting more traffic. Researchers globally have found lane kilometer to have a statistically-significant relationship with VKT. This impact has been quantified in the range of 0.5 to 1. Considering the above criteria and by varying the levels of induced traffic, the emissions were quantified to evaluate the impacts of induced traffic. Using an induced traffic elasticity of 1, the analysis shows that emissions typical national highway in India are higher by over 58% as compared to a scenario which excludes induced traffic considerations.  Under varying scenarios of elasticity from 0.25 to 1, the quantified emissions may range from 17 to 58% when tested for 3 different corridors.

An analysis of a typical corridor shows that induced traffic would reduce the initial year savings and would increase the emissions over the project lifecycle.

 

c.       Air quality impacts are highly correlated to CO2 emissions

In case the project provides CO2 reductions there is a huge likelihood that the project may provide similar air quality benefits.

% Increase with induced traffic ( elasticity 1)

	CO2	PM	Nox
Surat Manor	64	76	81
Salem Namakkal	80	82	82

  

d.      Construction of expressways make individual travel more efficient

It’s true that expressways due to high induced traffic may increase the emissions when compared with no project scenario. It’s also true that expressways make the individual travel better.  Over the project lifetime, it was found that the improvement is in the range of 20-25%. However, more traffic on the road nullifies the benefit and increases the total emissions.

e.    Road maintenance can impact the emissions profile of vehicles

By increasing the roughness from 2m/km to 4, 6 and 9 m/km, the emissions (CO₂ Tons/Km/Year) increase by 1.6, 3.3 and 5.8% respectively.  Thus by following good maintenance strategies, emissions can be reduced to a certain extent by keeping a check on emissions. More insights on impact of roughness can be found here.

f.      Construction Emissions should be considered in project analysis

Literature review and subsequent analysis indicated that the construction emissions are a significant fraction of total lifetime emissions. An analysis based on the quantity of construction materials used – cement, steel and bitumen indicates that the approximate emissions of a two lane to four lane improved highway is approximate 1100 tons/km. When all the quantities are considered including the emissions generated by machinery, the emissions range from 2100 to 2400 tons/km for high-speed roads  (four-lanes) based on traffic, topography and type of improvements suggested. The operations emissions calculated in the test corridors ranged from 1700 to 7000 tons/km indicating that for high speed roads, (at-grade four-lane highway) construction emissions can range from few months to maximum 2 years of operation emissions.

g.       Placeholders

The analysis of three corridors provided the following placeholders

•      CO2 Footprint  = 1100  Tons/lane-km/Year
•        CO2 Savings Indicator = -350 Tons/lane-km/Year ( - ve sign indicates increase in emissions when compared to BAU)

Please click here to read the entire report and access presentations. Comments can be mailed to sudhir(at)cai-asia.org.

IS MOTORCYCLE A SYMBOL OF FREEDOM?

Sudhir Gota

“Bike is the most democratic transport vehicle. Bike is the most daring, challenging as it gives its owner the tempting feeling of freedom, that is why one can say without any exaggeration, bike is a symbol of freedom” - Vladimir Putin

A recent comment by Russian Prime Minister Vladimir Putin on motorcycles as a means of democratic transport or as a symbol of freedom forced me to write a blog on motor cycles. Motorcycles are a unique mode of transport. Many people love to use it and many hate to see it. Based on my personal experience, I equate bikes with guns. It allows many to earn livelihood, reach hospitals and schools. But a single mistake can lead to several deaths!! 

Motorized two wheelers have exploded in numbers in the last two decades. In 2005, Asian countries accounted for 80% of the total world’s motorcycle fleet of 290 million units and 90% of world motorcycle sales. China accounts for 50%, with around 17 million units produced per year while Indonesia and India with around 5 million units per year and Vietnam with 2 million units per year.  The projections by experts suggest that the numbers would multiply in future as the technological solutions would increase the number of models while bringing the cost down.  Increasing travel distances in our cities with availability of cheap loans is making it easier for two wheelers to prosper….

Also, increasing number of two wheelers has resulted in formulation of contradictory policies. Some cities have banned the use of two wheelers while some are promoting it with facilitating measures such as free parking, availability of loans etc.  While the policy makers are still confused, the numbers are spiraling out of control. Increasing number of two wheelers are not only choking the streets but also magnifying the externalities.  Sometimes riding motorcycles can be as dangerous as playing with guns. The latest WHO report which analyzed the causes of accidents and policy measures suggested that:

“Our roads are particularly unsafe for pedestrians, cyclists and motorcyclists who, without the protective shell of a car around them, are more vulnerable. These road users need to be given increased attention. Measures such as building sidewalks, raised crossings and separate lanes for two wheelers; reducing drink-driving and excessive speed; increasing the use of helmets and improving trauma care are some of the interventions that could save hundreds of thousands of lives every year. While progress has been made towards protecting people in cars, the needs of these vulnerable groups of road users are not being met.”

Many Asian countries have initiated measures such as mandating the use of helmets to reduce the fatalities. Globally only 40% of countries have a motorcycle helmet law that covers both riders and passengers, and mandates that helmets should meet a specific national or international standard.   Use of helmets can save life of motorbike users as they can reduce the risk of head injury by 69% and death by 42%. Many Asian countries have initiated the mandatory use of helmets but implementation has been passive.  Some of the two wheeler measures initiated by Asian countries:

1.       Mandatory motorcycle helmet legislation

2.       Traffic calming measures

3.       Two- three-wheeler ban, 50-50 scheme etc.

4.       Electronic enforcement

5.       Road safety education (in primary schools)

6.       Separation of traffic

7.       Visibility enhancement

8.       Limiting the engine capacity

9.       Speed restriction

10.   Organizing motorcycle clinics

The following table indicates the status of helmet laws and its implementation.

	% of 2-3 wheelers in total road fatality	Helmet Law	Wearing rate
Thailand	70%	Yes	27%
Philippines	-	NA	34%
Malaysia	58%	Yes	70%
Indonesia	61%	Yes	93%
India	27%	Yes	-
China	28%	Yes	16%
VietNam	60%	Yes	85%
Bangladesh	8%	Yes	-
Brunei Darassalam	11%	Yes	98%
Singapore	48%	Yes	56%
Srilanka	-	Yes	-
Pakistan	32%	Yes	-
Nepal	33%	Yes	-
Combodia	63%	Yes	21%
Republic of Korea	21%	Yes	85%
Japan	18%	Yes	-

So what are the solutions for two wheelers in Asia?  Is it symbol of freedom or congestion and other externalities?   What do you think?