# città 30

## https://nation.cymru/wp-content/uploads/2023/09/Wales-20mph-Impact-Analysis-Report.pdf

- Independent analysis of vehicle speeds in the first week after the implementation of 20mph speed limits in Wales
- data is provided by connected vehicles that upload data anonymously to allow the assessment of vehicle speeds
- speeds have reduced by 2.9mph (12.8%) in the week following the change in limit
- in two roads of around 2.5km in length in Cardiff and Wrexham, median travel times increased by between 45 and 63 seconds

## https://www.europeandatajournalism.eu/cp_data_news/none-of-the-european-cities-that-lowered-the-speed-limit-to-30-km-h-regrets-it/

- Graz
- in the first two years of the policy, the number of traffic accidents decreased by 25 percent
- afraid that there would be an increase in traffic jams, but this was not the case according to available statistical data
- Helsinki
- personal injury decreased by 9 percent
- Zurich
- according to theoretical modeling, the number of people exposed to excessive traffic noise decreased by 73%
- Berlin
- speed limit applies to five main roads, significant improvements in air quality could be observed: especially the level of nitrogen dioxide decreased
- Hannover
- 30 km/h limit has no significant effect on the number of traffic accidents.
- areas with such a limit the number of cyclists and pedestrians increase, and more people use public transport as well

## https://www.abc.es/motor/reportajes/abci-30-bilbao-mas-accidentes-chapa-pero-menos-heridos-202011101341_noticia.html

- 13 hits in 2019 it has risen to 4 in 2020
- accidents have dropped from 57 to 32
- and the injured, from 70 to 36
- more accidents with material damage, from 74 to 85
- 1.85 % fewer vehicles (about 10,214 less) have entered the city
- 0.92 % fewer internal traffic vehicles on the streets of the city
- traffic light infringements have decreased by 43 per cent
- decrease in emissions, from 3 per cent in nitrogen dioxide (NO2), 9 per cent in nitrogen oxide (NOX) and 12 per cent in particulate matter (PM10)
- public transport, which has increased between 9 and 10 per cent
- use of the bicycle a decrease of 6,000 steps of private bikes and an increase of 17.90 per cent in the use of public rental bicycles

## https://www.viamichelin.it/magazine/articulo/edimburgo-riduce-la-velocita-in-citta-e-diminuisce-significativamente-gli-incidenti/

- numero di collisioni è diminuito del 40%
- incidenti mortali sono diminuiti del 23%
- feriti gravi del 33%

## https://www.lyon.fr/actualite/mobilites/ville-30kmh-un-premier-bilan-encourageant

- 22% drop in accident
- 40% reduction in the number of hospitalised injuries

## https://moustique.lalibre.be/actu/belgique/2021/12/24/mobilite-bilan-positif-apres-un-an-de-zone-30-a-bruxelles-221532

- In the first nine months of 2020, there were 11 deaths and 121 seriously injured, while in the first three quarters of 2021 the figure fell to 5 deaths and 100 seriously injured
- Brussels Environment notes that the sound levels drops from 1.5 to 4.8 dB(A)

## https://mobilite-mobiliteit.brussels/fr/news/quel-bilan-apres-3-ans-de-ville-30kmh-a-bruxelles

- visible decrease in the average speed over all roads
- It is mainly pedestrians (green) and car occupants (blue) who benefit from the new speed limits. For these two types of users, the lowest number of victims is reached since 2010. But the injured also fell among cyclists (in pink) and scooter users (in red)
- reduce road traffic noise by more than half in some cases. Decrease in levels, ranging from 1.5 to 4.8 dB(A) depending on the time period, the location, the type of traffic and the floor covering

## https://www.intelligenttransport.com/transport-news/143786/tfl-data-shows-20mph-speed-limits-significantly-reduce-collisions-london/#:~:text=TfL%20is%20now%20working%20to,and%20Haringey%20in%20March%202023

- number of collisions has reduced by 25% (from 406 to 304)
- collisions resulting in death or serious injury have also reduced by 25% (from 94 to 71)
- collisions involving vulnerable road users have decreased by 36% (from 453 to 290)
- collisions involving people walking have decreased by 63% (from 124 to 46)
- Analysis of journey times, traffic flows and speeds suggest that the 20mph speed limit has not increased congestion

## https://www.nrso.ntua.gr/geyannis/wp-content/uploads/geyannis-cp622.pdf

- Brussels
- Reduction in fuel consumption by 10%
- Reduction in traffic noise by 2,5 db
- Reduction in the number of road crashes by 50%
- Paris
- Reduction in noise pollution by 50%
- Reduction in the number of road crashes by 25%
- Reduction in those considered serious and fatal by 40%
- Munster
- Reduction in fuel consumption by 12%
- Reduction in the number of people severely injured in road crashes by 72%
- Bilbao
- Reduction in air pollution: 11,4% decrease in NO2-μm3, 17,1% decrease in NOX-μm3 and 19,1% decrease in PM10
- Reduction in the number of road crashes by 23%
- Edinbrugh
- Reduction in particulate matter (PM) by 8%
- Reduction in the number of road crashes by 38% including fewer crashes involving cyclists and pedestrians
- Zurich
- Reduction in traffic noise between 3dB and 5dB
- Reduction in fatalities in road crashes by 25%

## http://www.roadsafetyngos.org/wp-content/uploads/2023/03/Talking-points_-30kmh-zones.pdf

- Graz
- total number of crashes has decreased by 25%
- over 80% of all crashes in the city take place on through roads where the speed limit is still 50 km/h
- reduction of 12% in crashes involving minor injuries
- reduction of 24% in crashes involving serious injuries
- Crashes involving pedestrians decreased overall by 17% and those involving motorists by 14%
- Toronto
- 28% reduction in pedestrian crashes
- 67% reduction in serious and fatal injuries
- London
- 46% reduction in death and serious injury crashes overal
- 50% decrease in death and serious injury crashes for children aged 0–15
- death and serious injury crashes involving pedestrians and bicycle riders decreased by 35% and 38%, respectively
- Bristol
- city-level reduction in fatalities of 63%
- Warrington
- a reduction of 43% of serious and slight pedestrian injuries
- Brighton and Hove
- 327 (-45) casualties involving 0 (-1) fatal, 43 (-11) serious and 284 (-33) slight injuries

## https://ccnpps-ncchpp.ca/docs/2014-Built-Environment-A-30-kmH-Speed-Limit-on-Local-Streets.pdf

- Personal injury collisions pedestrians -32.4% cyclists -16.9%
- 0-15 years -46.2% -27.7%
- Killed or seriously injured -34.8% -37.6%
- 0-15 years -43.9% No data.
- (Swedish) average emissions reduction ranged from 2 to 4 dB(A) for cars and 0 to 2 dB(A) for trucks, with a supplementary reduction of 2 dB(A) for the maximum noise measure
- (German) reductions of average noise emissions of up to 3 dB(A) with reductions in maximum noise emissions of up to 5 dB(A)

## https://tfl.gov.uk/info-for/media/press-releases/2023/february/new-data-shows-significant-improvements-in-road-safety-in-london-since-introduction-of-20mph-speed-limits

- collisions involving a vulnerable road user have decreased by 36 per cent
- collisions resulting in death or serious injury have decreased by 25 per cent
- collisions involving people walking have decreased by 63 per cent

## https://www.pacts.org.uk/wp-content/uploads/Lustre-Report-2023-Funded-by-the-RST.pdf

- Grenoble
- 30% reduction in the number of collisions
- nearly 20% reduction in victims recorded annually
- decrease of at least 20% in the proportion of victims killed or seriously injured
- Schwerin
- collisions resulting in injury, the number of injured and killed went from 11+1 with 50 km/h, to 4+0 with 30 km/h, thus a reduction of almost 70%
- Hamburg
- total number of collisions in speed limited zones went down by 10%
- collisions involving injury or death decreased by 16%
- reduce the average noise level by around 3 decibels
- Reductions in air pollution and improvements in well-being were also measured
- Netherlands
- total number of collisions after the introduction of the 30 m/h zone measure had dropped by 10-15%
- number of casualties reduction may have amounted to double that figure
- other study in the Netherlands
- decrease in the number of injuries was calculated as 22%
- Sweden
- 25% reduction in the number of people killed in motor vehicle related collisions
- 10-15% reduction in the number injured
- Switzerland
- number of casualties decreased by around 15% in urban areas, and in rural areas by almost 50%
- decrease in collisions of 27.5% and of injuries by 28.8%. A meta-analysis by Elvik shows that speed 30 zones reduced the number of injured by an average of 27%

## https://www.racfoundation.org/assets/rac_foundation/content/downloadables/speed_limits-box_bayliss-aug2012.pdf

- HC emissions reduce with speed, whereas CO2 and PM ones have the lowest emission profiles at medium speeds
- At higher speeds tyre noise dominates that created by vehicles. Tyre-road noise increases strongly with speed, around 12 dB(A) for a doubling of speed

## https://democracy.edinburgh.gov.uk/documents/s9840/Item%207.3%20-%20Evaluation%20of%2020mph%20with%20appendices.pdf

- no evidence of displacement of traffic from 20mph streets to 30mph streets after implementation of the 20mph limit
- casualties have fallen substantially since implementation, but it is not yet possible to ascribe reductions to the 20mph limit as opposed to an overall falling trend
- pollutants do not give any cause for concern in relation to the impact of the 20mph limit

## https://www.gov.wales/sites/default/files/publications/2019-08/the-state-of-the-evidence-on-20mph-speed-limits-with-regards-to-road-safety-active-travel-and-air-pollution-impacts-august-2018.pdf

- 1mph average speed reduction there is a 6% reduction in urban traffic collisions
- children could not reliably detect a vehicle approaching at speeds higher than approximately 25 mph and did not reach adult levels of perceptual performance under most viewing conditions
- any investigation into air quality impacts these are reported as either negligible or a slight improvement
- assessed traffic speed levels of 30km/h or less were associated with higher odds of cycling

## https://academic.oup.com/jpubhealth/article/37/3/515/2362676?login=false

- effective in reducing accidents and injuries, traffic speed and volume
- such interventions are cost-effective
- positive attitudes to such schemes by local residents
- effects on physical activity—most notably walking and cycling and children playing outside—were less clear.

## https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/784907/technical-appendix-4-20mph-rapid-evidence-review.pdf

- the rate of collisions increases as vehicle speed increases and vice versa. In line with this finding, the risk of injury to pedestrians also increases as speed increases
- NOX emission factors were higher for petrol vehicles over 20mph drive cycles compared to 30mph drive cycles; for diesel vehicles they were lower. Given the higher contribution of diesel vehicles to emissions of NOX, this is an important result.
- PM10 emission factors are lower for both petrol and diesel vehicles at 20mph compared to 30mph, with the exception of vehicles with engines in excess of 2.0 litres.
- CO2 emission factors follow the same pattern as NOX showing increased fuel consumption when travelling at lower speeds.
- London Impact of 20mph drive cycle NOx -8.2% PM10 -8.3% CO2 -0.9%

## https://journalofroadsafety.org/article/32203-economic-impact-of-30km-h-benefits-and-costs-of-speeds-in-an-urban-environment

- Legislative, enforcement, and road engineering actions to reduce urban speed limits will not only reduce crash injuries and deaths, but will also provide significant cost savings and health benefits delivered by transport noise and air pollution reduction, and increased pedestrian and cyclist active mobility. Finally, lower urban speeds combined with sound urban street policies also facilitate public transport, reduced space for motorised vehicles in favour of non-motorised active transport, freeing up more space for urban recreation and commerce, delivering more liveable vibrant cities (Global Designing Cities Initiative, 2016).

## https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-019-8139-5

- Speed limit reductions from 40 km/h to 30 km/h were associated with a 28% decrease in the pedestrian motor vehicle collisions (PMVC) incidence rate
- 67% decrease in major and fatal injuries in the post intervention period on streets with speed limit reductions

## https://www.edinburgh.gov.uk/downloads/file/25178/city-of-london-emissions-report

## http://www.niassembly.gov.uk/globalassets/documents/raise/publications/2015/regdev/1715.pdf

## https://www.bmj.com/content/bmj/339/bmj.b4469.full.pdf

- The introduction of 20 mph zones was associated with a 41.9% (95% confidence interval 36.0% to 47.8%) reduction in road casualties, after adjustment for underlying time trends. The percentage reduction was greatest in younger children and greater for the category of killed or seriously injured casualties than for minor injuries. There was no evidence of casualty migration to areas adjacent to 20 mph zones, where casualties also fell slightly by an average of 8.0% (4.4% to 11.5%)

## https://injuryprevention.bmj.com/content/26/1/85

- between 2008 and 2016, the 20 mph speed limit intervention was associated with a city-level reduction of fatal injuries of around 63%

## https://20mphzonesnot20mphlimits.files.wordpress.com/2014/06/warrington-20-mph-pilot-scheme-full-report.pdf

## https://documents1.worldbank.org/curated/en/206691614060311799/pdf/Guide-for-Road-Safety-Interventions-Evidence-of-What-Works-and-What-Does-Not-Work.pdf

- 30 KM/H (20 MPH) ZONES FOR PEDESTRIANS are highly effective

## http://www.ncchpp.ca/docs/ReviewLiteratureTrafficCalming_En.pdf

## https://de.30kmh.eu/fakten-aus-europaeischen-staedten/graz/

- average speeds dropped only slightly, from 37.1 km/h to 36.6 km/h. On the other hand, the top speeds decreased, and the spread of the speeds showed a more homogeneous flow of traffic
- significant decrease in accidents involving personal injury. On the 80% of roads at speed 30, the accident rate (with 20% of accidents) is low. The majority of the 80% accidents are happening on the remaining fifth of the roads at speed 50
- risk of fatal accidents for children even decreased by 90%
- The noise measurement results on the roads at speed 30 returned up to – 1.9 dB(A)
- At minus 2%, NOx showed a slight relief for the entire urban area. On the Tempo-30 roads themselves, NOx decreased significantly at minus 24%.
- No negative impact on fuel consumption or a small decrease of to minus 1% was found

## https://mobilite-mobiliteit-brussels.prezly.com/bruxelles-ville-30-dernier-bilan-et-perspectives

- 20% reduction in the number of accidents in Brussels
- decrease in the number of seriously injured/dead is even more evident: -25%
- Spending from 50 to 30 km/h halves the noise nuisance caused by road traffic. Between 2.5 and 3.9 dB(A) depending on the type of coating

## https://jech.bmj.com/content/jech/77/1/17.full.pdf

- Small reductions in road traffic collisions were observed at year 1 (3%; p=0.82) and year 3 post-implementation (15%; p=0.31) at the intervention site. Difference-in- differences analyses showed no statistically significant differences between the intervention and control sites over time for road traffic collisions.
- little change in mean traffic speed at year 1 (0.2 mph, 95% CI −0.3 to 2.4, p=0.14) and year 3 post-implementation (0.8, 95% CI −1.5 to 2.5, p=0.17).
- For traffic volume, a decrease in 57 vehicles per week was observed at year 1 (95% CI –162 to −14, p<0.00) and 71 vehicles at year 3 (95% CI −213 to 1, p=0.05) post-implementation.

## https://futuretransport.info/urban-traffic-research/

- at a speed limit of 30mph (48.3km/h) CO2 emissions were found to be 29% greater than at a speed limit of 15mph (24.1km/h), and 35% greater than at 20mph (32.3km/h). For a diesel SUV, CO2 emissions are 54% higher at a speed limit of 30mph than at 15mph, and 38% higher than at 20mph.
- The optimum speed limit in city traffic for minimising CO2 emissions for a small petrol hatchback is around 17.5mph (28.2km/h), and for minimising NOx it is around 12.5mph (20.1km/h). For larger vehicles, diesels and SUVs, CO2 emissions are minimised at a maximum speed of 12.5mph.
- At a speed limit of 30mph NOx emissions were found to be 91% greater than at a speed limit of 15mph, and 79% greater than at 20mph