• Off-peak deliveries cut city congestion

  • Off-peak deliveries cut city congestion

    Local restrictions on night-time deliveries leave some distributors no choice but to dispatch trucks during morning rush hours.  But lifting these rules could reduce peak traffic volumes and increase transport efficiency, according to a recent study in Sweden.

    Some communities prohibit heavy trucks from operating during the night.  Stockholm is one of them, but the city wanted to see if lifting its ban might yield some benefits in transportation efficiency.  Acoustic, transport efficiency and policy researchers from the KTH Transport Research Laboratory joined with other partners in a pilot study with the city of Stockholm to see if lifting the 10.00pm-6.00am ban on truck deliveries made sense.

    They worked with a national supermarket chain and its suburban Stockholm central warehouse, as well as with a company that supplied food to restaurants and hotels.

    Ordinarily the supermarket warehouse, 30km north of Stockholm, would deploy several fully-loaded trucks to make deliveries during peak morning rush hours from 6.00 to 8.00, because there is no way for one truck to make them all in that short a time span.

    But in the study, a single truck delivered goods to three stores in central Stockholm between the prohibited hours.  It would return to the warehouse three times in the night to be reloaded, and then make its subsequent delivery.  “That's one truck doing the work of three – or in other words, morning commuters are spared having to share the road with three heavy duty trucks,” Anna Pernestål Brenden of KTH said.

    Although it was a small scale study, she said there were strong indications that scaling up off-peak deliveries could increase business efficiency for suppliers and retailers, reduce fuel consumption and CO2 emissions, and perhaps make a positive impact on traffic volume during peak morning hours. 

    Part of the study was also to assess whether deliveries at night bothered neighbours.  The drivers had to follow some rules: for example, no using reverse signals or talking on cell phones outside the vehicle.  Also, two trucks equipped with low noise technology were used.

    “It turned out that the noise people complained about was caused mainly by unloading the truck, not driving,” Anna explained.  KTH created a sound recording system that placed microphones in the truck.  The front microphones would record when the truck was getting unloaded, so that neighbourhood background noise could also be taken into account.  The system allowed researchers to evaluate the mix of sound from both vehicle and environment, and give a true picture of what difference the unloading of the vehicle actually made.

    One particularly quiet neighbourhood on the edge of the city was the source of complaints from neighbours – but Anna said the results showed that most people don’t notice the unloading in neighbourhoods with sufficient background noise:  “Only in the quiet neighbourhoods does noise raise a problem.”

    The study involved truck manufacturers, goods owners, carriers, goods receivers, and companies that make silent roller cages.  KTH was also asked to validate new technologies, such as a zone management concept for electric hybrid vehicles.  This system would automatically switch the engine to electric, rather than diesel, power in certain geographic zones.

    Anna described the study as a “small step” for more efficient transport, adding:  “By making small changes we can improve transport efficiency, reduce congestion, and enable new business models for goods receivers.”