Evidence on performance
Variable work hours in Ottawa
Staggered Work Hours in Manhattan
Flexible Hours at De-centralised Offices in the United Kingdom.
The first flexible working hours experiments were in the 1950s, although it was not until the late 1960's early 1970's that the use of such practices became widespread. Schemes were usually promoted by the local authority; some as a reaction to the fuel crisis of the time, others as a means of reduce peak hour congestion on public transport (mainly in North America) and the roads (mainly in Europe). Since then, flexible working hours have become fairly standard business practice, offered as a means of providing good working conditions rather than reducing peak hour congestion. Consequently, many examples of flexible working hours to influence travel time are now rather dated. Additionally, their influence may be dwarfed by increases in employment and car use. However, the early examples do illustrate what flexible working hours can achieve. If all those who currently work 08:00 to 16:00 or even 08:30 to 16:30 were to work 09:00 to 17:00 current peak hour congestion would be even worse. Additionally, in an environment where public transport is largely provided by the private sector a measure that spreads demand is likely to ensure frequent services over a longer period.
Impacts on demand
There has been a small increase in public transport use in the morning and evening peak hours after the introduction of the flexible working hours programme. It is possible that the programme allowed commuters to fit their journeys to public transport timetables, but the introduction of new and additional express bus services may also have been influential. Nevertheless, Safavian and McLean (1975) conclude that there is, "no evidence of a change in mode toward a greater use of the automobile - a shift that could be induced as a consequence of a reduction in congestion on the road system".
In terms of the distribution of demand for public transport, it is flatter in the morning and evening peak period after the implementation of flexible working hours, despite the increase in patronage. The increase in patronage is thought to reflect the greater comfort achieved during peak hours through less congested vehicles.
In terms of the distribution of demand for road space by car drivers, the change in the morning was minimal - the peak 15 minutes occurred a quarter of an hour earlier and the distribution was slightly flatter. In the evening the difference was more noticeable, as the peak began half an hour earlier and was considerably flatter, with approximately 20% less traffic on the roads at the most congested point in evening peak. These changes are reflected in the demand for car park spaces during the peak periods. There is no evidence that the programme had an impact on car occupancy rates, which is positive in as much as it indicates that flexible working hours do not necessarily result in a reduction in ride sharing
Impacts on supply
Contribution to objectives
Staggered working hours differ subtly from flexible working hours in that employees choose from a choice of staggered start times - in this case, participants were given the choice of 08:30 to 09:30 with finish times adjusted accordingly. The chosen start time becomes the daily start time unless the choice is re-negotiated. Staggered hours were seen as beneficial as they ensured a change in start time sufficient to change departure time. If an employee chose to start only 15 minutes earlier or later, it was feared that any change in departure time would be too insignificant to spread demand. Interestingly, 92% of participating workers chose to start at 08:30 - the same time as that chosen by many given complete flexibility in the Ottawa experiment.
Impacts on demand
"A substantial and continuing reduction in congestion [in terms of passengers using public transport] of 6 per cent in the peak 15 minutes has been observed at three of the busiest Transit authority subway stations" (O'Malley and Selinger, 1973). The number of passengers has decreased by 26% in the peak 15 minute period (09:00 to 09:15) and increased by 24% between 08:30 and 08:45. Evening peak travel was monitored at a different station and revealed a reduction in passenger numbers of 18% between 17:00 and 17:15, and an increase of 53% between 16:30 and 16:45, when additional train capacity was also available.
1 = 09:00 to 09:15 2 = 08:30 to 08:45
Lift waiting times were monitored at three bank buildings in Lower Manhattan. The maximum waiting time decreased from six minutes to two minutes as a result of the staggered working hours. The average peak period delay decreased from two and a half minutes to one.
As a result of these changes, employers reported increased punctuality amongst their employees. This is a result of "fewer and less [severe] transportation delays earlier in the morning peak" (O'Malley and Selinger, 1973). It is possible that the pattern of delays could spread with the peak spreading, as the staggered working hours programme was rolled out to more employers over a wider area of Manhattan. However, no evidence is presented in either direction.
As a consequence of the positive impacts of the staggered working hours programme in Lower Manhattan, it was rolled out to other areas of district.
Impacts on supply
"85 percent of the employees sampled had a favourable overall reaction to the project [and] the changed hours had very few negative effects on efficiency. In fact, some organisations reported positive gains in work effectiveness. [Additionally], a substantial majority of unit heads surveyed reported that no severe communications problems resulted from the changed hours" (O'Malley and Selinger, 1973).
Employees were asked, "on the new schedule, does the workday seem to you to be longer, shorter or about the same?" "Three times as many felt the day was 'shorter' rather than 'longer' under the new schedules. [Additionally], four times as many were 'more satisfied' with their jobs than were 'less satisfied'. Further to this, "almost 50 per cent of those who changed their work schedules reported that they were 'more satisfied' with their trips to and from work" (O'Malley and Selinger, 1973).
Respondents were also asked whether their domestic routines had changed, and whether the changes were positive or not. It was found that, "whilst certain changes did occur, they were almost always viewed positively by the participants" (O'Malley and Selinger, 1973).
Contribution to objectives
Daniels (1980) noted that there were differences between the up take rate by offices between regions concluding that, "on the evidence available here flexible hours seem more acceptable in offices located in provincial towns and cities". It was also noted that larger organisations are more likely to implement flexible working hours.
Impact on demand
On average, over all the offices included in the study, peak arrivals as a percentage of all trips generated decreased by 11 per cent in the first seven weeks of flexible working hours, and decreased a further two percent after 25 weeks. The morning peak 15 minutes also shifted from 08:00-08:15 to 07:45-08:00. The ability of flexible hours to spread demand was reflected by the keenness of staff to start and finish early to avoid congestion. It is notable that in both the UK and the US, fewer staff chose to start late, possible as a result of family circumstances.
It is also noted that after several months of flexible working hours, staff tend to adopt regular start and finish times (e.g. 08:30 to 16:30 every day). This could merely shift congestion problems if the majority of employees in an area are on flexible working hours and choose these times.
Daniels also notes that whilst there is "only a marginal difference between the trip times and distances of the two groups [those working flexible hours and those not] for the data as a whole, there are differences between areas. In metropolitan areas, it appears that workers are taking the opportunity to live further away from work without incurring travel time costs.
In terms of mode choice, Daniels (1980) notes "the spreading of peak hour travel is largely attributable to office workers who travel to work as car drivers or passengers. Office workers who use public transport are constrained to a greater degree by bus or train timetables". This is in contrast the US examples cited above, where flexible working hours was seen as facilitating public transport use. "There was also some evidence of a long term trend towards a higher proportion of staff arriving at the office as car drivers as a result of the FWH [flexible working hours]" (Daniels, 1980). It is possible that either staff who previously travelled by public transport could not take advantage of flexible working hours without driving, due to timetable constraints, or that some used public transport purely because it was too congested to drive during the peak. The evidence of the impact of flexible working hours on ride sharing is ambiguous. Nevertheless, there is a suggestion that, "a proportion of office workers on flexible hours are still working with fixed starting and finishing times in mind but perhaps with earlier or later arrival times in order to miss local congestion but not at the expense of non-participation in car sharing" (Daniels, 1980).
It is interesting that more efficient journeys to work and better time keeping are not seen as benefits for either employers or employees.
Impact on supply
Contribution to objectives
Gaps and weaknesses