Road congestion generates on average 30% more time to travel by car between a town in the urban area and the center of Bordeaux. This is one of the conclusions of a vast survey carried out by the Observatory of Mobility and Life Rhythms of A’Urba, the Bordeaux-Aquitaine Urban Planning Agency.
The observatory analyzed travel times by car from Google Maps data between the town hall of Bordeaux and the town halls of the municipalities of its urban area (perimeter which extends over a large part of the Gironde), in both directions, between 2017 and 2021. The results are calculated on the average of Tuesdays and outside school holidays, and are compared with the average time observed at three in the morning.
In 2021, at the morning rush hour (8 a.m.), 56 minutes are needed, on average, to reach Bordeaux City Hall from the municipalities of its urban area and 51 minutes in the evening (5.30 p.m.) in the ‘other way. A difference which is explained by “a more spread out evening peak”, specifies Mireille Bouleau, urban planner and specialist in econometrics at A’Urba. Traffic generates 20 minutes in the morning and 15 minutes in the evening of additional travel time, compared to the “empty” time, i.e. one third on average of the total travel time: 35% to Bordeaux in the morning and 29% in the evening in reverse.
The year 2021 marks “a return to the pre-pandemic level”
First observation of A’Urba: “in the morning, the average weather returns to the level of 2017” after a period 2020-2021 disrupted by the pandemic. In the evening, it deteriorates since it is 4.5 minutes longer than in 2017. If we compare to 2019, the year preceding the pandemic and during which the level of congestion had increased, “there is only at the morning rush hour in the inbound direction to Bordeaux that travel times have not returned to their pre-crisis level. »
Between 7.30 a.m. and 10 a.m., the situation was indeed more congested in 2019 than in 2021. On the other hand, from the outskirts to Bordeaux, off-peak hours and the evening “counter-peak” were greater in 2021 than in 2019 Ditto from Bordeaux: travel times during off-peak or peak hours, morning and evening, also exceeded their 2019 level.
“Even though the health situation was not completely restored”, the year 2021 thus marks “a return to the pre-pandemic level” notes the study. The monthly curves even show an increase in travel times from April to November. “The end of 2021, which can be considered as a return to normal in terms of health, marks a strong increase in journey times, especially in the morning. “We are even starting to have congestion at off-peak hours, whether in the morning or in the evening, observes Mireille Bouleau, with in particular congestion in the opposite direction, that is to say in the evening in the direction entering Bordeaux, because there are more diversified reasons for travel, with leisure and shopping trips. »
“Teleworking does not yet seem massive enough to make traffic flow more smoothly”
How to explain this so rapid return to “pre-pandemic” traffic levels? If the pandemic “has led to an increase in teleworking, it has also generated disaffection [en 2021] for public transport in favor of the car and the bicycle”, underlines the study. “Travel times show that the phenomena compensate for each other, and teleworking does not yet seem massive enough to make traffic more fluid. »
Another sign of the low impact, for the moment, of teleworking: the differences between the days of the week are small and have also changed little. “Wednesdays and Friday mornings are slightly less congested than Mondays, Tuesdays and Thursday mornings to Bordeaux. In the other direction, the differences are even smaller. The pandemic does not seem to have changed these rhythms of life. If teleworking has developed, it is either not widespread enough, or it is distributed relatively evenly over the different days of the week. This point goes against a preconceived idea of telework which would have been accentuated on Mondays and Fridays. »
“Congestion is played out at the crossings of the Garonne or at the entrance to Bordeaux”
“We also notice major territorial differences,” insists Mireille Bouleau. “The situation is not at all homogeneous throughout the agglomeration. In the morning towards Bordeaux, we observe a more congested situation on the right bank and along the A62, with journey times which have increased by 20% or even 30% in five years. Congestion is clearly at stake at the level of crossings of the Garonne or at the entrance to Bordeaux at the level of boulevard Moga, and these black spots impact all this territory. Conversely, there are territories for which the situation is improving, in particular near sections of the bypass that have been converted to 2×3 lanes, such as Mérignac. Even in the Cubzaguais, where we start from a very difficult situation, it seems that things are going a little better. »
In the evening in the direction of the returns, the travel times increase for “all the east of the agglomeration, in particular for the communes between Carbon-Blanc and Léognan, and all along the A89. »
The icing on the cake: “in five years, there has been an increase in the variability of traffic times”, points out the town planner. “This means that there are terrible days, with uncertainty about the journey times increasing. This growing uncertainty plays a big role in the feelings of motorists. »
If there is hardly any improvement to be seen, at least for the next few months, at least we can note that with average travel speeds which vary between 14 and 19 km/h in the morning for the municipalities of heart of the agglomeration, “the bicycle, for these municipalities, is relevant and could be competitive with the car. »