Zuid-Holland has the first CO2-negative way

On 1 November, the first CO2-negative road of The Netherlands, the N211, was put into use between The Hague and Poeldijk.

The sustainable road is the result of a special pilot in which the Province of Zuid-Holland in collaboration with the market, went looking for the best mix of new and advanced innovations to use in the road. From new materials and production processes to traffic measures and solutions that generate or save energy in and along the road. This climate-friendly approach is the starting point for new road maintenance projects in Zuid-Holland and can also be used as a blueprint for roads elsewhere. Floor Vermeulen, Regional Minister of the Province of Zuid-Holland, officially opened the CO2-negative road.

Sustainable During Work And Use

The major maintenance of the N211 emits 4,000 tons of CO2, while during the work and the lifetime of the road, up to 14,000 tonnes of CO2 will be saved compensated by measures in and around the road. The construction, maintenance and management of roads are a core task of the Province. To achieve the climate targets, it was a logical step to examine how much CO2 could be saved in the process. Heat generation from the cycle path, asphalt that is processed at low temperature, wooden bus shelters and crash barriers, and fungi that remove tar from old asphalt are merely a selection of the 20 innovations that Zuid-Holland, construction company BAM Infra and engineering consultancy Sweco applied in the road. In addition to CO2 reduction, an important condition was that the innovations could be applied in other roads as well.

Total approach for new road projects

"We didn't put all our eggs in one basket," said Regional Minister Floor Vermeulen. "The CO2 savings do not depend on one large, promising innovation, but are achieved by an integrated approach, during which some innovations have been applied, that had already been tested, but were not yet ready for the market. Zuid-Holland, in its capacity of launching customer, has given the final push to prepare these innovations for the market." "Innovations of tomorrow" have also been considered. They are being tested in special testing grounds. The approach and objectives of the N211 and its 'sibling' N470 have meanwhile been copied in all new road projects of Zuid-Holland. The Province will share knowledge it has gained about the process and the measures with other authorities.

From major maintenance to climate ambition

The N211 was on the planning for major maintenance. The foundation had to be renewed, as well as the sheet piling that separates the road from the waterway next to it. This was the ideal scenario for Zuid-Holland to find out how such a project could be approached fundamentally differently. Citizens and businesses along the road were involved early on and asked to join in. In the invitation to tender, construction companies were challenged to save as much CO2 as possible. The Province consciously chose to invest in the process. Vermeulen: "The N211 shows that it is possible, so during new maintenance projects, concentrating on CO2 emissions will be the standard. The market can then meet that demand with the latest developments."

Principals are key

BAM Infra won the contract in cooperation with 14 innovative companies, that jointly applied 20 sustainable innovations in and along the road. "We would prefer to innovate in every road. The principal is key in that", says Marcel Geleijnse, project manager of BAM Infra. "The bar for the N211 was just slightly higher than the prevailing one in the market, but you can see that as long as you gather good partners around you, an awful lot is possible."

Uniform CO2 standard forms the basis

Engineering Consultancy Sweco supervised the major maintenance and translated Zuid-Holland's ambition in the preliminary stages into a draft-design and a CO2-footprint. The main challenge was the creation of a uniform standard to grant CO2 savings to a very wide range of innovations. Project Manager Jeroen Drost of Sweco: "We have done this in good dialogue with the contractors. Cooperation was the key to success in this project."

Visible and invisible innovations

Road users cannot escape the exceptional result when using the road. Innovations such as the wooden bus shelters and crash barriers certainly draw the attention, as does the dynamic road lighting that dims when there is little traffic at night.

But the most important innovations are not immediately visible. The red tiles of the cycle path are indistinguishable from regular cement tiles, but the use of so-called geopolymers as a substitute for cement makes them much more sustainable. A heat collector has been integrated in another part of the cycle path. This 'reverse floor heating' gathers solar heat from the road surface and stores it underground to be used to heat commercial properties later on. Cathodic protection allows a low voltage electric charge of the waterway's new sheet pile wall, to stop it corroding. It could therefore be made thinner. The old concrete wall has been crushed and reused as the foundation of the new road. In addition, BAM Infra used an asphalt mixture that is produced and processed at low temperature. This has an extra smooth finish to reduce the rolling resistance of motor vehicle tyres and is less elastic, so that vehicles sink less into it at micro scale. Each of these is an innovation and contributes to the road's total CO2 reduction.  Part of the testing ground were promising innovations to be tested in practice in this project for the first time, such as cleaning tar asphalt with special fungi and the generation of construction power with a generator that works on the clean fuel hydrazine.

Maximise Value

During the preparatory phase, Zuid-Holland explicitly stimulated construction companies and engineering firms to get acquainted with innovative companies that could play a role in the redesign of the road. A part of the innovations in the final road was generated by that process. In addition, a cooperation with the Municipality of Westland led to the replacement of both the waterway's sheet pile walls and the installation of solar panels in a part of the cycle path. Businesses along the road have participate in the CO2 reduction by placing solar panels on their roofs on a large scale.

However, even after the reopening of the road, new innovations are being added. Last week, the contract to make all road signs along the road of bamboo was signed. This will be placed shortly.

Road users also benefit

The CO2-reduction is not a one-off. The solar panels and the heat from the cycle path will supply energy for years after the road has reopened. Citizens and businesses benefit directly from the road design that improves the traffic flow and by the application of smoother asphalt that reduces the rolling resistance of motor vehicle tires. This last measure saves the motor vehicles on the road 2.5% in fuel and emissions.

Using N211 creates energy

The reason for this project is the provincial's target for 2025, to cut back the CO2 footprint of its road management and maintenance by 50% compared to the level in 2015, en route to CO2 neutrality in 2050. This objective has been put into practice in the maintenance of the N211 and N470.

For these pilot roads, the Province of Zuid-Holland invites authorities, businesses and citizens to look at mobility in a different way. On the N211 the Province has worked with innovative companies on solutions that save and generate energy. The result includes a cleaner road and an improved traffic flow. The road is a practical testing ground for innovation and cooperation. Successful innovations can be scaled up to other roads.