Issy-les-Moulineaux is one of the municipalities of Greater Paris, located in the southwest of the urban agglomeration. Due to its location and economic vitality, this area of the Paris Region faces substantial traffic volumes because many people from the whole Paris area transit to or through Issy for work by car.

In this context, Issy-les-Moulineaux is one of the major digital and employment pole of the Region as it hosts 180 companies over 20 employees for a total of about 70,000 people working in Issy. Most of these people come from all over the region as just about 3,000 inhabitants of Issy-les-Moulineaux declare to be working in the municipality.

The Paris urban agglomeration is ranked as the 41^st most congest world area (in 2018)[1], according to TomTom Index, making it as an average congested metropolitan area. Actually, always according to the Tomtom ranking Paris is the less congested city between the “Megacities”[2] and it is 14^th if also consider large Cities.

At the same time, the biggest problem of the agglomeration is the population density (8,622 people/Km²⁾ that is one of the largest in Europe. Issy follows the trend, having a population density of more than 16,000 inhabitants per squared kilometre.

Figure 1. Modal shares distribution of Issy-les-Moulineaux residents[3]

Moreover, just 41,5% of workers in the Region go to work by car (27% in Issy), showing how inhabitants already have a good behaviours, but this is still to be improved as congestion during peak hours is always around 70%.

In France, Cities are not on-top of SUMPs[4], this is a competence of the Region that has set some objectives for the period between 2010 and 2020[5], namely:

• Reduction of use of cars of 2%
• Increase of use of public transports of 20%
• Increase of walking and biking of 10%

One of the most important projects to reach these goals is the delivery of a new automated metro ring around Paris to better connect the various cities of its suburbs and to improve connections with airports. This project will allow to improve mobility in the long term, but it will be completed between 2030 and 2035, in the meanwhile it will have various phases, starting its roadworks in 2018 in various points in and around Issy-les-Moulineaux (see map below), will see several phases of roadworks which will make Cities and other local authorities face increased traffic volumes and, more generally, congestion issues and high pressure on transport services.

The portion of metro in Issy-les-Moulineaux will be completed between 2024 and 2025.To this end, being Issy part of a huge urban agglomeration Issy needed as a first step to define the potential consequences of the roadworks, started in early 2018, on its territory, mainly two in the first year of the project:

• Closure of various roads in Boulogne Billancourt, just next to Issy (point 1 in map above)
• Closure of a main road in the heart of Issy, next to the local train station Issy RER (point 2 in map above)

Figure 2. Main roadworks and deviations in Issy

According to estimations, the first point might have a more detailed impact as the closure will be longer (up to 2021) and the competent authorities (the department) had proposed to drivers passing daily from Issy as reported in the map below (green lines).Then, Issy needed then, as a starting point, to understand the consequences of the scheduled roadworks and to be able to define mitigating actions to tackle any issues arising from them.

Notes:

[1] https://www.tomtom.com/en_gb/trafficindex/city/paris

[2] The others are Moscow, Istanbul and London.

[3] Data referring to home-work usual behaviours, Census 2015, INSEE

[4] Sustainable Urban Mobility Plans

[5] This document is available, in French, in the “Policy elements” section