The development of urban infrastructure is not only the construction of new water and sewer networks, but also their renovation and modernization. Traditional open-cut methods, although still used, often cause significant disruptions to road traffic, generating additional costs and frustration for residents. In contrast, trenchless technology, particularly gravity drilling, allows the same tasks to be completed faster, cheaper and – crucially – without disrupting everyday life in the city.
Real-life example: renovation of the sewer network on a main street
Imagine a situation in the centre of a large city, e.g. Gdańsk. It was necessary to replace a section of sanitary sewer about 150 metres long, running under one of the main streets, serving around a dozen thousand vehicles daily.
- Traditional scenario (open-cut): To carry out the work, at least one traffic lane would have to be closed for about 6–8 weeks. Drivers would be redirected to detours, and public transport schedules would require adjustments.
- Trenchless scenario (gravity drilling): Using trenchless technology makes it possible to lay a new sewer pipe within 10 days, without the need to stop traffic and without excavating the road surface.
Comparison: traditional method vs. trenchless technology:
Criterion
Open-cut method
Trenchless technology
Completion time
6–8 weeks
10 days
Direct costs
Lower equipment costs, but high pavement restoration costs
Higher technology cost, no pavement restoration costs
Indirect costs
Significant: detours, traffic jams, losses for local businesses
Minimal or zero
Impact on residents
Noise, dust, restrictions on pedestrian and vehicular movement
Works almost unnoticeable
Durability of the solution
Dependent on the quality of pavement restoration
Stable, without interference with existing infrastructure
Analysis of social and economic costs
Traditional excavation of a street in the city centre generates so-called social costs that are rarely taken into account in investor calculations, yet have a real impact on the city's economy.
- Detours and traffic jams: According to data from the General Directorate for National Roads and Motorways, the average cost of an hour lost in a traffic jam in an agglomeration is about 35 PLN per car (including fuel and driver time). With 10,000 vehicles per day this amounts to as much as 350,000 PLN in losses per week.
- Difficulties for local businesses: Restaurants, shops and service outlets in the work zone often record turnover declines of even 20–30%.
- Impact on public transport: Bus detours mean additional fuel costs and delays in services that affect passengers.
In the case of trenchless technology, all these factors are practically eliminated. Shorter completion times and the absence of street closures mean that the city saves hundreds of thousands of PLN in indirect costs.
What would have happened if trenchless technology had not been used?
If the traditional method had been used in the example described, the city would have had to deal for two months with:
- permanent traffic jams,
- resident dissatisfaction,
- reputational losses (media criticism, social frustration),
- the need to carry out costly pavement restoration,
- additional expenses related to public transport detours.
Meanwhile, trenchless technology allowed the same task to be completed quickly and almost unnoticed by the surroundings.
In summary - minimizing disruption to urban traffic is not only a matter of residents' convenience but also measurable economic savings. Trenchless technology, especially gravity drilling, enables the modernization and construction of sewer networks in a modern, safe and efficient way. Comparing detour costs, completion times and impact on the local economy, it is clear that investing in trenchless methods brings the city and its residents far greater benefits than traditional excavations.
Comments: The importance of avoiding disruption to urban traffic through trenchless technology