In 2015, the Dubai Municipality defined affordable housing as a living space for people whose salary is between Dh3,000 to Dh10,000 per month. As a rule of thumb, housing is usually considered affordable if it costs less than 30 percent of gross household income. However, in 2014, the average annual expenditure on housing and utilities as a percentage of total household expenditure was higher in Dubai than in other major cities, which indicates that many households in Dubai were overburdened by the cost of housing. A more visible sign of the shortage of affordable housing options is the traffic congestion caused by daily commuters, who live in more affordable housing in the northern emirates while working in Dubai.