Work has begun on a £100m business development in north Oxfordshire.
Catalyst Bicester, just off the A41, will cover about 300,000 sq ft (27,870 sqm), and provide 1,750 new jobs, according to property developer Albion Land.
Buildings will start becoming available for businesses to use from 2022.
However, cycling campaigners have criticised the developers for "numerous shortcomings" and council planners for not making the site easier to get to.
About 12 buildings will be based at Catalyst Bicester, for use by advanced manufacturing and technology businesses.
It will include a David Lloyd health club, with a gym, swimming pools, racquets courts, café and restaurant.
Simon Parsons, from Albion Land, said: "Our focus now is to complete the highway works to ensure that the project is connected to the cycle, foot and bus network and to construct the first phase of technology buildings to respond to the high demand in the area from knowledge-based businesses."
But George Bennett, chair of Bicester Bike Users' Group, said it would be "quite inconvenient" to walk or cycle to the site.
He said: "The most glaring problem is the new access roundabout that only allows cyclists to navigate the roundabout in limited directions."
The existing paths were also "narrow and shared with pedestrians" which had "built-in zig-zags around the street lights, rather than relocating them", he added.
"At some stage the roundabout and the access to the development will need to be upgraded to properly support growth in walking and cycling, but the funds are likely to have to come out of public funds."
The plans for the new development were approved by Cherwell District Council in May.
Cherwell District Council, and the highways authority Oxfordshire County Council, have been asked for comment.