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In general, modal split was influenced by all the changes in the city, but the Access Control and Road Pricing Schemes played major roles, as already highlighted. Before and after data show that, in 2002, modal split in the central area was 30% public transport, 27% private cars, 23% motorbikes/mopeds and 20% pedestrians. The 2005 data revealed that these proportions had switched to 31%, 22%, 24% and 23%, respectively. The most important result is the decrease of private cars in favour of three point increase (percentage) for walking, thus suggesting that citizens reduced their use of the car for trips of short distances.


The benefit of the Access Restriction is also evident when traffic flows and illegal through-traffic are considered: the former decreased by 20% during the restriction periods and by 15% in the morning peak hour (8.30-9.30). The proportion of illegal accesses decreased from 18% to less than 10% of the total traffic flows, during the four years of the gates implementation (even though, currently, still about 20.000 vehicles/week illegally access the area).


Data analysis performed during the period between 2006 and 2008 confirmed this trend and also the number of accesses during the same period is resulted quite stable (around 70,000 vehicles/day), except during Christmas time (10th – 20th December) when different ZTL rules have changed the access rate.


The benefit of access restriction is also evident when considering traffic flows and illegal through-traffic: the former decreased by 20% during the overall restriction period and by 15% in the morning peak hours (8.30 – 9.30). Since e-gates were implemented, the proportion of illegal accesses decreased from 18% to less than 10% in respect of total traffic flows. Despite of that still now 20,000 vehicles per week illegally access the LTZ area. The analysis of 2008 data on access violations confirms that about 4,000 fines are emitted during every working day and during the whole year roughly one million of sanctions have been issued. 

Hence, the general objective of reducing the impact of traffic on the environment and increasing the level of protection of the city centre can be considered achieved.

An appreciable reduction in air pollution was measured: the comparison, in terms of concentrations, between the annual mean values, recorded in 2001 and the mean values in 2004 showed a reduction of CO concentration of about 21%, PM10 of 11% and Benzene of 37%. In particular, results concerning benzene concentrations seem to be particularly relevant since, if just 2005 is considered, a 27% decrease was recorded at about 50 sites.

Also emissions strongly decreased and exceeded expectations. The number of polluting vehicles decreased e.g. non-catalysed mopeds reduced by about 45%, private cars by 37% and commercial vehicles by slightly less than 35%. However the main influence on this was a ban on diesel and gasoline fuelled vehicles not meeting Directive 91/441/CE requirements from circulating in the Rail Ring area, which came into force in January 2002.

Regarding the Trastevere and San Lorenzo ACS+RP schemes, pollution concentrations surveyed in the central LTZ and in two districts with passive sampler campaigns are in line with the decrease observed at urban level; the most positive outcomes were recorded at Trastevere rather than at S.Lorenzo, but the different morphology of the two districts along with other factors such as the differences of time of implementation can contribute to such discrepancy.


Even more significant, in the San Lorenzo district, are the results for noise pollution. During the monitoring of area, after the implementation of the measure, in zones without commercial activities a reduction of noise pollution of 8-9 dB(A) was observed. In zones with commercial activities such as restaurant or pubs, the reduction of noise pollution was slight and was about 3-4 dB(A).

A complete analysis was carried out on the basis of the annual mean values in three significant air quality measurement stations of the Regional network, namely:


  • A station located within the historical city centre LTZ (Arenula);
  • A station situated outside the LTZ but in a congested area of the city (Via Magnagrecia);
  • A station placed within a green area outside the LTZ (Villa Ada).

Carbon monoxide (CO) values metered during last ten years show a constant decrease in all three station considered. This is mainly due to cars engines technical improvements and also to mobility management activities introduced.

On the contrary, PM10 value metered during last ten years show a substantial difference between the readings of the city centre station with respect to the other two considered. While these last two had a constant trend during the period between 1998 and 2001, the Arenula station registered a decrease of more than 30% in PM10 concentration between the same period.

This is mainly due to the coming into force of the e-gates in 2001 and it is clearly reflected in the decrease of number of days in which the PM10 concentration overcomes the UE threshold value reached by the Arenula readings with a decrease of more than 50. 

As a preliminary conclusion and by considering that NO2 concentration values do not evidence any definitive behaviour, we could state that the introduction of the LTZ scheme controlled by e-gates has anyway supported Rome Municipality environmental policies.