Post-COVID Peak Hour Traffic Demand Management

POST-COVID PEAK HOUR TRAFFIC DEMAND MANAGEMENT - CAN WE DO BETTER?

Gleb Kolenbet, Principal Integrated Transport Engineer, Moreton Bay Regional Council

This paper was delivered at IPWEAQ’s SEQ Branch conference in February.

Commuting by car is more popular than public transport (PT) in South East Queensland (SEQ). Car commuting is less efficient than PT: it significantly increases congestion during peak times and comes at various costs, including economic, health, social and environmental. While the apparent answer to fixing congestion is to upgrade road infrastructure, more roads create an ‘induced demand’ and promote more congestion. Recent events associated with the COVID-19 pandemic management in SEQ saw unprecedented measures such as restrictions on people’s movement and complete lockdowns. During the peak of restrictions in April 2020, peak hour congestion and patronage on PT dropped significantly, while active travel participation (mainly cycling) increased. At around the same time, the Australian Government announced that the country entered a recession and began prompting the economy by introducing stimulus programs and fast-tracking infrastructure spending. A record $110 billion land transport infrastructure program was announced, spanning over the next 10 years. Local Roads and Community Infrastructure programs had a 200% ($1 billion) fund injection, totalling a $1.5 billion commitment year on year. By August 2020, many restrictions were lifted as SEQ entered a recovery mode. Most of the workforce that worked from home during the height of the pandemic began returning to workplaces and the traffic congestion worsened. February 2021 recorded higher congestion levels compared with the same period of 2020 and 2019. The recent traffic congestion data is concerning as it draws commuters to driving instead of using PT. ‘Fixing’ congestion isn’t simple. It requires a holistic approach towards improved commuter demand management in the future. Transport planning professionals and policymakers should explore initiatives including working from home (WFH), flexible start times and double shifts for schools, and increasing investment into PT and active travel networks to manage travel demand better and encourage modal shift away from a private vehicle.

Despite the transport infrastructure investment efforts by all government levels, the private vehicle remains by far the most popular mode of commuting to work in greater Brisbane and SEQ (Figure 1) (.idcommunity, 2020). According to transport planners, private vehicles are the least favourable option because every private car occupant produces an average of 11 times the congestion compared to a bus passenger (Thomson and Bull, 2006).

The reliance on cars over public transport (PT) for daily commuting stems from post-war planning that re-directed many cities’ future by favouring cars (Woodcock, 2019). The population of SEQ has grown increasingly and many suburban growth corridors are spread across vast areas, making the daily commute longer, especially during am and pm peaks. PT remains a less popular choice because private

vehicles are affordable and offer a fast and efficient way to travel. Between 2009-2018 the per capita PT patronage on a bus and heavy rail in SEQ had decreased (Figure 2) (Moore, 2019). This is supported by Census statistics, which shows that between 20112016 the number of commuters using PT had reduced while commuting by car as the driver became more popular (Figure 3).

As a result of favoured private car commuting, Brisbane was ranked the second city in Australia, after Sydney, for the longest mean daily commute (Figure 4), (Ye and Ma, 2019).

Further examination of peak hour commute patterns shows that the roads become over-utilised during congested peak periods and are otherwise under-utilised (Figure 5), (Hubbard, 2009). While the peaks only last a few hours, peak hour design is common for infrastructure planning and design. Subsequently, infrastructure investment decisions are made based on the worst-case scenario and may lead to under-utilisation of the network outside of peak hours.

To better understand the reasons behind the above statistics, several factors are examined. One of the main aspects influencing commuter behaviour is the infrastructure upgrades (assumed as road, PT and active travel infrastructure). The researched statistics for road and transport infrastructure investment vary. According to the Australian Government (2010), several levels of governments invested heavily into multiple congestion-busting and capacity upgrade projects in SEQ. Brisbane and its outer metropolitan areas received new busways, rail links, arterial roads and motorway extensions and upgrades. In 2018, the State Government announced a record investment in road and transport infrastructure for 20182022, exceeding previous years’ commitments.

Contrary to that, another report in 2020 suggested that the net per capita expenditure on infrastructure in QLD and SEQ over the past few years was lower than New South Wales and Victoria (Wardill, 2020). Overall, a significant part of governments’ expenditure is on transport infrastructure.

This is echoed by Australian Government announcement in April 2020 warning about the proceeding recession but also ‘prompting’ the economy by introducing stimulus programs and fast-tracking infrastructure spending. A record $110 billion land transport infrastructure program was announced, spanning over the next 10 years. Local Roads and Community Infrastructure programs had an unprecedented 200% ($1 billion) increase, totalling a $1.5 billion commitment year on year (Australian Government, 2020).

Additional data indicates that more than 77% of net debt will be accumulated by Queensland, New South Wales and Victorian

Figure 1. Method of travel to work greater Brisbane and SEQ derived from ABS Census (.idcommunity, 2020).

Figure 2. Bus and heavy rail patronage in SEQ for 2009-2018, linear statistics indicate a decline in passenger numbers (Moore, 2019).

state governments by 2023-24 (Hutchens, 2020). This is alarming as the increasing net debt could potentially reduce the states’ ability to continue funding and expand transport infrastructure programs.

Apart from the infrastructure investment factor affecting commuter mode choice, other reasons are investigated to explain why the commuters choose to drive a car to work overtaking PT and why the roads become congested despite major upgrades and new road links being constructed. A further analysis applying economics paradoxes theories is explored.

The ‘Rebound Effect’ and ‘Induced Demand’

In the 19th century, the economist William Stanley Jevons observed that as coal became cheaper, consumers used more coal. The ‘Jevons Paradox’ was observed in other areas, including traffic congestion, also known as the ‘rebound effect’ (Leunig, 2010). Similarly, drivers will fill up the road infrastructure capacity over time, causing it to reach peak capacity and create traffic congestion. Later research by engineers and scientists lead to a more targeted and trafficspecific explanation of Jevons Paradox. The ‘Downs-Thompson Paradox’ further confirmed that the expansion of major highway and arterial type roads leads to increased congestion by creating an induced demand and in some cases undermines scale economies of a competing transit service (e.g. PT), leaving users of both modes worse off (Zhang et. al, 2016). Further studies by the German mathematician Dietrich Braess revealed that adding a road to an already congested traffic network increases overall journey time, which is now called Braess’s Paradox (Chen, 2016).

Can we just put up with traffic congestion?

It is evident that congestion is a recurring event despite infrastructure investment, so how can we overcome it?

Figure 3. Change in travel method to work between Census 2011 and 2016, relative to % of employed people. The car/driver commute had the most significant growth while travel by train and bus decreased (.idcommunity, 2020).

Figure 4. Mean daily commute time for major cities in Australia, Brisbane commute in 2017 is the longest in the country after Sydney (Ye and Ma, 2019).

Figure 5. Peak-period congestion showing road underutilisation outside peak periods, (Hubbard, 2009).

Figure 5. Observed congestion profile for Brisbane in May 2020, compared with 2019 and 2018. There is a noticeable reduction in peak profile (extended peak) and a change in peak time. Peal extension around school travel time is explained by increased car travel to schools instead of PT (Saunokonoko, 2020).

Can society just put up with it? Even though congestion is sometimes necessary and can’t be avoided, heavily congested networks come at a significant price to society, because of the follow-on effects. For example, the congestion on major SEQ roads alone costs the economy nearly $160 million annually (RACQ, 2020). Also, according to Zhang and Batterman (2013), in many cases vehicles emissions have become the dominant source of air pollutants and the increasing severity and duration of traffic congestion have the potential to degrade air quality, particularly near main roadways and cause adverse health effects. Another significant consequence of congestion is the infrastructure overdesign and excessive expenditure on roads and freeways. Overdesign stems from the approach to infrastructure planning and design using the worst case (peak hour) scenario as a design service standard. The social cost of increased congestion also can’t be disregarded. Excessive time spent sitting in traffic impacts people’s personal lives including less time spend with family and friends and less time exercising and socialising. Traffic congestion also impacts people’s happiness, where they choose to live and how productive they are at work (McCosker, 2018).

Traffic congestion can negatively impact our society on many accounts, so engineers and planners should find a way to manage it. But how can we ‘fix’ its persistent occurrence aside from the conventional investment into ‘congestion busting’ infrastructure upgrades?

In drawing parallels with several paradox theories, it can be concluded that the rebound effect causes the traffic peak hour congestion in SEQ and the traffic demand is induced by the available (new and upgraded) road infrastructure. As road infrastructure reaches capacity and the subsequent new upgrades are completed more consumption occurs, causing traffic congestion and undermining the alternative PT modes such as buses and trains. Similarly, infrastructure upgrades in alternative routes create temporary relief and ultimately increase overall commute time (Zhang et al, 2016).

COVID-19 - effects on commute

In early 2020, the world began experiencing the effects of COVID-19. Tragically, many lives were lost, and the impacts are continuing today. Aside from health and economic impacts, there were also substantial changes to the way we commute. In SEQ, changes in everyday commuting resulted from lockdowns and the introduction of flexible work from home (WFH) options and school closures.

The speed with which the transport sector felt COVID-19

Figure 6. Observed road congestion levels in Brisbane for the first week of February 2021 show a sharp increase in congestion post-COVID compared with 2020 and 2019 records (Hosier, 2021).

impacts was significant, with road, rail and bus systems experiencing free-falling declines in customer numbers almost overnight (Johnstone et.al, 2020).

A decrease in traffic demand resulted in noticeable declines in traffic delays. A reduction in traffic demand resulted in reduced congestion, especially on networks with fewer routing alternatives (Du et. al, 2020). This discovery echoes the paradox theories discussed earlier, only in reverse - less demand equals less delay, especially for less complex networks. So, what can we learn from the COVID-19 effects on traffic congestion for future planning?

Working from home (WFH)

Work-related commute effects on the am and pm peaks are significant as most commuters drive to work. During the height of the restrictions in April and May 2020, Brisbane’s peak hour congestion levels reduced by about 50% resulting in welcomed relief from the usual peak hour roads over-utilisation (Figure 5).

School trips

According to PTC (2015), school trips contribute to 5-10% of peak hour traffic. Research suggests that over 60% of children get to school in a car either as a passenger or a driver, while only a quarter regularly walk or ride (ACT Council of P&C Associations, 2013). Even a lesser number of students take PT.

Public transport (PT)

PT patronage plummeted during the peak of pandemic restrictions. The main reasons were: (a) capacity - PT network becomes inefficient if the passenger capacity is reduced due to strict distancing requirements, and (b) commuter’s perception that PT is unsafe because of a higher chance of infection transmittal (which is not completely unfounded). In addition, Brisbane had switched off almost 1000 parking meters in the city areas (Daoud, 2020), while most private carparking facilities also reduced parking fees. As a result, many exPT commuters turned to driving a car.

Post-COVID-19 congestion - the new normal?

As the restrictions eased in SEQ in the second half of 2020, many commuters working from home began returning to work and school and traffic numbers rose. As a result of perceived risk of potential community transmission, commuter confidence in using PT remained low. Many parents turned to car travel for school trips, resulting in an adjustment of the peak hour period and added extra car trips onto the network. School-related peak periods were extended and lasted longer (Figure 5).

By February 2021, private car trips soared to record high levels. Peak hour road congestion was worse than in 2020 and 2019 (Figure 6), (Hosier, 2021). The only positive sign of the post-COVID traffic environment was a sharp uptake in active travel including bicycles and e-scooters.

WFH or working remotely

During the height of restrictions, Queenslanders worked from home 58% of the time. According to Global Workplace Analytics (2020) around 60% of employees have a job where at least some of their task can be done remotely including managers, professionals, clerical and admin and sales (Hensher and Beck, 2020). Further studies show that desks are vacant 50-60% of the time.

Despite worldwide devastation, COVID-19 restrictions allowed for an alternative way to managing traffic congestion - many commuters worked from home and there were significant changes to school traffic. While these measures are unlikely to continue long term, there are lessons that can be learned from this experience. The following part of the paper looks at demand management tools, which if implemented can improve congestion and encourage modal change. Each item is given a hypothetical percentage for contribution to congestion reduction.

WFH can make a significant difference in reducing the number of commuters and relieving peak hour traffic congestion. According to Morse (2019), employees who can work remotely are happier and prepared to work longer hours. They are more productive and have a better work-life balance.

Score: 10-15% reduction in congestion based on the reported effect of WFH during March-September 2020 (Hensher and Beck, 2020).

Improved PT network coverage, service frequency and commuter safety

Authorities must make PT more attractive to commuters. This includes better price point, improved network coverage and connectivity, better frequency and safety (including hygiene in line with pandemic management plans). It is estimated that 21% of car trips can be removed from networks by PT which is a significant number of trips enough to make a substantial difference to peak hour congestion.

Score: 10-15% (conservative estimate)

Flexible start and finish times and compressed working weeks at workplaces

This is different from WFH and assumes that some employees would still travel to work outside the peak commute times. This can be achieved either by altering start and finish times and compressing a 5-day week into 4-day week.

Score: 2-5% (estimated)

Flexible start and finish times - schools

By selectively changing a schools start and finish time, the timing of school travel (either by PT or by car) will shift outside of usual peak hour. This measure will be dependent on workplace flexibility for parents to start work later. Some Brisbane schools including Fortitude Valley State Secondary College have already adjusted start times.

Score: 1-3% (estimated), akin to flexible workplace start score

Double-shift schooling

Double shifts (am and pm) are introduced at selected schools. The impact on traffic congestion may be two-fold: reduced peak and additional traffic at off peak due to a different travel pattern to suit the double-shift study commute. This measure may be extreme, but it has the significant additional benefit of costefficiency by utilising the existing infrastructure.

Score: 1-2% (estimated), although the effects of extended peak need to be examined carefully

Improved active travel network and end of trip facilities

This measure which has the benefits of a more active and healthier community.

Score: up to 1% (estimated)

Other key tools such as road pricing (congestion tax, distance or time-based fees, tolls etc.) and land use planning initiatives (increased density near PT nodes etc.) were not reviewed as part of this paper.

A 25%-46% congestion reduction is derived by adding all the scores. The lower (25%) score represents a conservative estimate however, it can provide a significant reduction in peak traffic, enough to improve congestion considerably.

Summary

Private car commuting remains a popular choice in SEQ and causes peak hour congestion, resulting in productivity loses, increased pollution, and negative health and social impacts. There is a high cost to the economy. Several theories, including Jevons, Downs-Thompson and Braess’s Paradoxes explain that investing in road infrastructure alone cannot provide long-term relief from congestion. Congestion rates plummeted during COVID-19 due to restrictions and changes in commuter behaviour including less trips because of WFH and distance education. However, by February 2021 congestion rates have soared, surpassing previous year’s levels. A holistic approach to congestion management identifies several initiatives that can significantly reduce congestion and possibly redirect some of the road infrastructure funding to PT and active travel networks to promote and support a modal shift away from private car commute.

The author is happy to provide references upon request.

ABOUT THE AUTHOR

Gleb is a principal integrated transport engineer with diverse experience in land development planning and engineering in local government and utilities. Gleb’s interests are traffic demand management, transport planning and modal change in growth areas. He is an RPEQ, a member of AITPM and a vicepresident of IPWEAQ SEQ branch.